Recombinant herpes simplex virus-2 expressing glycoprotein b and d antigens

ABSTRACT

The present invention is directed to Herpes simplex-2 viruses that may be used in vaccines to immunize patients against genital herpes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/626,438 filed Feb. 5, 2018, the content of which is incorporated herein by reference in its entirety.

GOVERNMENT SUPPORT

This invention was made with Government Support under Grant No R56 AI 93738 awarded by the National Institutes of Health. The Government has certain rights in the invention

SEQUENCE LISTING

The instant application contains a Sequence Listing which has been submitted electronically in ASCII format and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Jan. 30, 2019, is named 043214-080293WOPT_SL.txt and is 83,579 bytes in size.

TECHNICAL FIELD

The present invention is primarily concerned with vaccines that can be used to immunize subjects against Herpes Simplex Virus type 2 (HSV-2) infections associated with chronic genital ulcers. The vaccines use a replication defective HSV-2 virus that has been engineered to express high levels of both HSV-2 glycoprotein B antigen (gB2) and HSV-2 glycoprotein D antigen (gD2).

BACKGROUND

Herpes Simplex Viruses (HSV) and HSV Infections

Herpes simplex virus 2 (HSV-2) is the primary cause of genital ulcer disease. It can cause both an acute, productive infection and a long-term latent infection characterized by unpredictable periodic recurrences (Whitley, et al., Clin. Infect. Dis. 26:541-553; see also 554-555 (1998)). Apart from causing lifelong recurrent genital ulcers, HSV infections are a major concern in AIDS patients. It has been documented that genital HSV-2 infection triples the risk for sexually acquiring HIV infection (Freeman, et al, Aids 20:73-83 (2006)), and in Africa, this increase in risk may contribute to 25-35% of incident HIV infections (Abu-Raddad, et al., PLoS ONE 3:e2230 (2008)).

Although the severity and duration of most symptomatic HSV primary infections can be reduced by oral or intravenous treatment with acyclovir, valacyclovir, or famciclovir, antiviral therapy neither prevents the establishment of latent infection from primary infection nor reduces subsequent recurrences (Whitley, et al., Clin. Infect. Dis. 26:541-553; see also 554-555 (1998)). The continued spread of genital herpes in the United States over the past decades (Fleming, et al., N. Engl. J. Med. 337:1105-11 (1997); Bradley, et al., J Infect. Dis. 209(3):325-333 (2014)) and the increasing incidence of HSV resistant to current antiviral medications suggest that there is a need for safe and efficacious vaccines against HSV infections (Koelle, et al., Annu. Rev. Med. 59:381-395 (2008); Stanberry, Herpes 11 (Suppl 3):161A-169A (2004)). In addition, the finding that HSV suppressive therapy leads to a significant reduction in levels of HIV in the genital mucosa and plasma of women infected with both HSV-2 and HIV (Nagot, et al., N. Engl J. Med. 356:790-9 (2007)) suggests that an effective HSV vaccine may also have major implications in control of HIV infection (Abu-Raddad, et al., PLoS ONE 3:e2230 (2008); Koelle, et al., Annu. Rev. Med. 59:381-395 (2008)).

HSV-2 Glycoproteins D and B

HSV glycoproteins gD2 and gB2 are abundantly expressed on the surface of infected cells (Glorioso, et al., J. Virol. 50:805-12 (1984)) and constitute the major glycoproteins on the viral envelope (Handler, et al., J. Virol. 70:6067-70 (1996)). They are essential for virus entry into cells and are major targets for neutralizing antibodies against HSV (Sim, et al., J. Gen. Virol. 19:217-33 (1973); Para, et al., J. Virol. 55:483-8 (1985); Cohen, et al., J. Virol. 49:102-8 (1984); Minson, et al., J. Gen. Virol. 67(Pt 6):1001-13 (1986); Sanchez-Pescador, et al., J. Infect. Dis. 166:623-7 (1992); Cheshenko, et al., J. Gen. Virol. 83:2247-55 (2002)). gD2 and gB2 are also the dominant viral targets for both CD4⁺ and CD8⁺ T cells in humans, and in murine models of HSV infection (Mikloska, et al., J. Gen. Virol. 79:353-61 (1998); Chentoufi, et al., J. Virol. 82:11792-802 (2008); Zarling, et al., J. Immunol. 136:4669-73 (1986); Johnson, et al., J. Immunol. 145:702-10 (1990); Wallace, et al., J. Virol. 73:7619-26 (1999); Kim, et al., J. Immunol. 181:6604-15 (2008); Sheridan, et al., J. Virol. 83:2237-45 (2009); Koelle, et al., J. Clin. Invest. 91:961-8 (1993); Koelle, et al., Virol. 68:2803-10 (1994); Tigges, et al., J. Virol. 66:1622-34 (1992); Hosken, et al., J. Virol. 80:5509-15 (2006)). Based on their biological importance, gD and gB are prime candidates for HSV subunit vaccine development (Stanberry, Herpes 11(Suppl 3):161A-169A (2004)).

In a phase 3 clinical trial, Stanberry et al. showed that vaccination with recombinant HSV-2 gD (gD2) in combination with adjuvant AS04 (gD2/AS04) provided 73-74% efficacy in protecting against the development of genital herpes in HSV-seronegative women. However, no significant protection was observed in men or HSV-1 seropositive subjects (Stanberry, et al., N. Engl. J. Med. 347:1652-61 (2002)). In more recent phase 3 clinical trials, no protection against HSV-2 disease or infection was observed (Belshe, et al., N. Eng. J. Med. 366:34-43 (2012)). Notably, the gD2/AS04 vaccine elicits little or no CD8⁺ T cell response (Belshe, et al., N. Eng. J. Med. 366:34-43 (2012); Koelle, et al., Annu. Rev. Med. 59:381-395 (2008)) and this response is crucial in controlling primary and recurrent HSV infection as well as preventing reactivation of HSV from latently infected neurons (Koelle, et al., J. Clin. Invest. 101:1500-8 (1998); van Lint, et al., J. Immunol. 172:392-7 (2004); Wakim, et al., Immunol. Cell. Biol. 86:666-75 (2008); Liu, et al., J. Exp. Med. 191:1459-66 (2000); Zhu, et al., J. Exp. Med. 204:595-603 (2007); Knickelbein, et al., Science 322:268-71 (2008); Zhang, et al., Mucosal Immunol. 2:129-43 (2009); Milligan, et al., J. Immunol. 160:6093-100 (1998); Schiffer, et al., Proc. Natl. Acad. Sci. USA 107:18973-8 (2010)). These studies highlight the need to develop HSV vaccine candidates capable of eliciting broader and more robust humoral as well as CD4⁺ and CD8⁺ T-cell responses to gD2 and other HSV antigens (Jones, et al., Herpes 11:12-7 (2004); Koelle, et al., Annu. Rev. Med. 59:381-395 (2008); Cohen, J., Science 330:304 (2010)).

Viral Vaccines

It is well documented that live viral vaccines capable of de novo synthesis of immunogens in the host induce a broader and more durable immune response than vaccines consisting of only peptides or proteins. Various forms of replication-defective HSV and neuro-attenuated, replication-competent mutants have been developed and tested as potential vaccines against HSV infection (U.S. Pat. No. 7,223,411; Dudek, et al., Virology 344:230-9 (2006)). However, because both replication-defective viruses and neuro-attenuated mutants can co-replicate with wild-type virus or become replication-competent in the context of wild-type virus, their use as a vaccine in humans poses a safety concern, particularly in individuals who harbor latent HSV infection (Koelle, et al., Curr. Eye Res. 30:929-42 (2005)). The observation that replication-defective HSV-1 mutants can reactivate the latent HSV-1 immediate-early promoter in the rodent brain has raised additional safety concerns about the possibility of such recombinants triggering outbreaks of productive viral infections in latently infected individuals (Starr, et al., Gene Ther. 3:615-23 (1996)).

To minimize the risk of activating latent wild-type infections, an HSV-2 vaccine that expresses a dominant-negative HSV replication initiating polypeptide, UL9 mutant (UL9-C535C), was generated (U.S. Pat. No. 8,809,047; Akhramayeva et al, J. Virol. 85(10): 5036-5047 (2011); Zhang et al, PLoS ONE 9(6): e101373. doi: 10.1371). This replication defective HSV-2 recombinant vaccine, also referred to as CJ2-gD2, encodes 2 copies of the HSV-2 gD2, and is more effective than the gD2 subunit vaccines. Immunization with CJ2-gD2 elicits effective HSV-2 specific neutralizing antibody and T-cell response, as well as inhibits wild-type latent infections.

While significant progress has been made with respect to potential HSV-2 vaccination for clinical use, there continues to be a need in the art for vaccines that can achieve a robust immune response, that minimize the potential of activation of latent wild-type virus, and that are easy to produce.

SUMMARY OF THE INVENTION

In general, the present invention makes use of tetracycline gene-switch technology (T-REx, Invitrogen/ThermoFisher Scientific) (Yao, et al., Hum. Gene Ther. 9:1939-50 (1998)) and uses deletion of essential genes or a dominant-negative mutant form of the HSV-1 or HSV-2 UL9 polypeptide, e.g., UL9-C535C to make the virus replication-defective and safe for immunization against HSV-2.

More specifically, one aspect of the present invention described herein provides a replication-defective, Herpes simplex virus-2 (HSV-2) recombinant viruses that lacks the sequences encoding functional ICP0 protein and gG2 protein and which comprise within the HSV-2 genome: (a) a first coding sequence, wherein said first coding sequence encodes HSV-2 glycoprotein B (gB2); wherein said first coding sequence is operably linked to a first immediate-early promoter, (b) a second coding sequence, wherein said second coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a second immediate-early promoter, and (c) a third coding sequence, wherein said third coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a third immediate-early promoter.

In some embodiments, said first promoter is an HSV-1 or HSV-2 immediate early promoter that is optionally operably linked to a first tetracycline operator (tet-O) sequence; said second promoter is an HSV-1 or HSV-2 immediate early promoter that is optionally operably linked to a second tetracycline operator (tet-O) sequence; and said third promoter is an HSV-1 or HSV-2 immediate early promoter that is optionally operably linked to a third tetracycline operator (tet-O) sequence. In one embodiment, at least one promoter is operably linked to a tetracycline operator (tet-O) sequence.

In another aspect of the invention described herein is a replication-defective HSV-2 recombinant virus, comprising within its genome (a) a first coding sequence, wherein said first coding sequence encodes HSV-2 glycoprotein B (gB2), wherein said first coding sequence is operably linked to a first promoter, and said first promoter is an HSV-1 or HSV-2 immediate early promoter that is operably linked to a first tetracycline operator (tet-O) sequence; (b) a second coding sequence, wherein said second coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a second immediate early promoter, wherein said second promoter is operably linked to a second tet-O sequence; and (c) a third coding sequence, wherein said third coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a third immediate early promoter, wherein said third promoter is operably linked to a third tet-O sequence. In one embodiment, the second promoter and third promoter are a HSV-1 or HSV-2 immediate early promoter.

In one aspect of the invention, the genome of the replication defective recombinant virus does not encode functional ICP0 and functional gG2. In certain embodiments, the genome of the replication defective recombinant virus does not encode functional ICP0 and functional gG2, and further does not encode functional UL19 (VP5 protein).

In still another aspect of the invention described herein is a replication-defective HSV-2 recombinant virus, comprising within its genome: (a) a first coding sequence, wherein said first coding sequence encodes HSV-2 glycoprotein B (gB2), wherein said first coding sequence is operably linked to a first promoter, and said first promoter is an HSV-1 or HSV-2 immediate early promoter that is operably linked to a first tetracycline operator (tet-O) sequence; (b) a second coding sequence, wherein said second coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a second HSV-1 or HSV-2 immediate early promoter, wherein said second promoter is operably linked to a second tet-O sequence; and (c) a third coding sequence, wherein said third coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a third HSV-1 or HSV-2 immediate early promoter, wherein said third promoter is operably linked to a third tet-O sequence.

In certain preferred embodiments, a non-essential gene encoding HSV-2 glycoprotein G (gG2), has been disrupted by the insertion of an HSV-2 glycoprotein B (gB2) sequence. In one embodiment, the first coding sequence is located at the gG2 locus of the HSV-2 genome and gG2 is not expressed. This preferred embodiment is counter-intuitive, as insertion at this location removes expression of the gG2 antigen, and thus this antigen can no longer contribute to overall immunogenicity of the vector. However, we have demonstrated that the recombinant viruses of the invention provide surprisingly strong and protective immune responses even in the absence of gG2 antigen. One advantage of this is that, since the loss of gG2 does not prevent HSV-2 viral replication (Liljeqvist, et al., J. Virol. 73:9796-802 (1999); Harland, et al., J. Gen. Virol. 69(Pt 1):113-24 (1988)), one can produce gG2 deletion mutants in cells that do not need to be engineered to produce compensatory gG2. An additional advantage is that assays, e.g., by PCR or serological tests, can be performed to determine whether gG2 is being expressed in the vaccinated host in order to differentiate between infection with wild type HSV-2 and with the vaccine vector. This ability may be important in serological differentiation for breakthrough HSV-2 infections in clinical settings.

In some embodiments, a dominant-negative mutant form of the HSV-1 or HSV-2 UL9 polypeptide, e.g., UL9-C535C, is used to develop a safe recombinant viral vaccine against HSV-2 infection. A reference providing guidance on how to make and use HSV-2 vaccines based on this technology is provided by U.S. Pat. No. 8,809,047 (incorporated herein by reference in its entirety).

In certain embodiments of various aspects, the recombinant virus is a dominant-negative virus that further comprises a fourth coding sequence, wherein said fourth coding sequence encodes a dominant negative mutant HSV-1 or HSV-2 UL9 protein, and is operably linked to a fourth promoter, wherein said fourth promoter is operably linked to a fourth tet-O sequence.

In certain embodiments of various aspects, the recombinant dominant-negative virus further comprises a fifth coding sequence, wherein said fifth coding sequence encodes a dominant negative mutant HSV-1 or HSV-2 UL9 protein, and is operably linked to a fifth promoter, wherein said fifth promoter is operably linked to a fifth tet-O sequence.

In one aspect of any of the embodiments, described herein is a replication-defective Herpes simplex virus 2 (HSV-2) recombinant virus, comprising within its genome: a) a first coding sequence, wherein said first coding sequence encodes HSV-2 glycoprotein B (gB2), wherein said first coding sequence is operably linked to a first immediate-early promoter; b) a second coding sequence, wherein said second coding sequence encodes HSV-2 glycoprotein D (gD2), and is operably linked to a second immediate-early promoter; c) a third coding sequence, wherein said third coding sequence encodes HSV-2 glycoprotein D (gD2); and is operably linked to a third immediate-early promoter; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein, and does not comprise a sequence encoding functional HSV-2 gG2 protein.

In one aspect of any of the embodiments, described herein is a replication-defective Herpes simplex virus 2 (HSV-2) recombinant virus, comprising within its genome: a) a first coding sequence, wherein said first coding sequence encodes HSV-2 glycoprotein B (gB2), wherein said first coding sequence is operably linked to a first immediate-early promoter, and said first promoter is an HSV-1 or HSV-2 immediate early promoter that is operably linked to a first tetracycline operator (tet-O) sequence; b) a second coding sequence, wherein said second coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a second immediate-early promoter, wherein said second promoter is operably linked to a second tet-O sequence; c) a third coding sequence, wherein said third coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a third immediate-early promoter, wherein said third promoter is operably linked to a third tet-O sequence; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein, and does not comprise a sequence encoding functional HSV-2 gG2 protein.

In some embodiments of any of the aspects, said second promoter and third promoter are a HSV-1 or HSV-2 immediate early promoter operably linked to a tetracycline operator (tet-O) sequence.

In some embodiments of any of the aspects, the first coding sequence is located at the gG2 locus of the HSV-2 genome.

In some embodiments of any of the aspects, said genome further does not comprise a sequence encoding a functional UL19 (VP5) protein.

In some embodiments of any of the aspects, the recombinant virus further comprises a fourth coding sequence, wherein said fourth coding sequence encodes a dominant negative mutant HSV-1 or HSV-2 UL9 protein, and is operably linked to a fourth promoter, wherein said fourth promoter is operably linked to a fourth tet-O sequence.

In some embodiments of any of the aspects, the recombinant virus further comprises a fifth coding sequence, wherein said fifth coding sequence encodes a dominant negative mutant HSV-1 or HSV-2 UL9 protein, and is operably linked to a fifth promoter, wherein said fifth promoter is operably linked to a fifth tet-O sequence.

In some embodiments of any of the aspects, said fourth sequence encodes UL9-C535C.

In some embodiments of any of the aspects, the recombinant virus comprises said fifth sequence, wherein said fifth sequence encodes UL9-C535C.

In some embodiments of any of the aspects, each of said first, second and third promoters are HSV-1 or HSV-2 immediate early promoters.

In some embodiments of any of the aspects, each of said first, second and third promoters are selected from the group consisting of an ICP0 promoter, an ICP27 promoter, and an ICP4 promoter.

In some embodiments of any of the aspects, the first promoter is a HSV-1 or HSV-2 ICP0 promoter.

In some embodiments of any of the aspects, the first promoter is a modified HSV-1 or HSV-2 ICP0 promoter comprising a human cytomegalovirus (hCMV) TATA element.

In some embodiments of any of the aspects, the first promoter comprises SEQ ID NO: 08.

In some embodiments of any of the aspects, the fourth and fifth promoters are hCMV immediate-early promoters.

In some embodiments of any of the aspects, said first sequence is a codon optimized sequence.

In one aspect of any of the embodiments, described herein is a replication-defective Herpes simplex virus 2 (HSV-2) recombinant virus, comprising within its genome: a) a first coding sequence, wherein said first coding sequence encodes HSV-2 glycoprotein B (gB2), wherein said first coding sequence is operably linked to a first immediate-early promoter, and said first promoter is an HSV-1 or HSV-2 immediate early promoter that is operably linked to a first tetracycline operator (tet-O) sequence; b) a second coding sequence, wherein said second coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a second HSV-1 or HSV-2 immediate-early promoter, wherein said second promoter is operably linked to a second tet-O sequence; c) a third coding sequence, wherein said third coding sequence encodes HSV-2 glycoprotein D (gD2) and is operably linked to a third HSV-1 or HSV-2 immediate-early promoter, wherein said third promoter is operably linked to a third tet-O sequence; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein, and does not comprise a sequence encoding functional HSV-2 gG2 protein.

In one aspect of any of the embodiments, described herein is a replication-defective HSV-2 recombinant virus, comprising within its genome: a) a first coding sequence, comprising a codon optimized HSV-2 gB2 sequence operably linked to a first promoter, wherein said first promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a first tet-O sequence; b) a second coding sequence, comprising a codon-optimized HSV gD2 sequence operably linked to a second promoter, wherein said second promoter is an HSV-1 ICP4 promoter that is operably linked to a second tet-O sequence and wherein the second coding sequence operably linked to the second promoter is located at the UL26/UL27 intergenic region; c) a third coding sequence, comprising a codon optimized HSV gD2 sequence operably linked to a third promoter, wherein said third promoter is an HSV-1 ICP27 promoter that is operably linked to a third tet-O sequence, wherein the third coding sequence operably linked to the third promoter displaces the UL19 gene; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein, and does not comprise a sequence encoding functional HSV-2 gG2 protein.

In one aspect of any of the embodiments, described herein is a replication-defective HSV-2 recombinant virus, comprising within its genome: a) a first coding sequence, comprising a codon optimized HSV-2 gB2 sequence operably linked to a first promoter, wherein said first promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a first tet-O sequence; b) a second coding sequence, comprising an HSV-2 gD2 sequence operably linked to a second promoter, wherein said second promoter is an HSV-1 or HSV-2 ICP0, ICP4, or ICP27 promoter that is operably linked to a second tet-O sequence; c) a third coding sequence, comprising an HSV-2 gD2 sequence operably linked to a third promoter, wherein said third promoter is an HSV-1 or HSV-2 ICP0, ICP4, or ICP27 promoter that is operably linked to a third tet-O sequence; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein, and does not comprise a sequence encoding HSV-2 gG2 protein.

In some embodiments of any of the aspects, the first coding sequence is located at the gG2 locus of the HSV-2 genome.

In some embodiments of any of the aspects, said genome does not comprise a sequence encoding a functional UL19 (VP5) protein.

In some embodiments of any of the aspects, the replication-defective HSV-2 recombinant virus further comprises i) a fourth coding sequence, encoding a dominant negative UL9-C535C protein, and operably linked to a third promoter, wherein said third promoter is an hCMV immediate early promoter that is operably linked to a third tet-O sequence; and ii) a fifth sequence, encoding a dominant negative UL9-C535C protein, operably linked to a fifth promoter, wherein said fifth promoter is an hCMV immediate early promoter that is operably linked to a fifth tet-O sequence.

In some embodiments of any of the aspects, the first promoter is an HSV-1 or HSV-2 ICP0 promoter.

In some embodiments of any of the aspects, the first promoter is a modified HSV-1 or HSV-2 ICP0 promoter comprising a human cytomegalovirus (hCMV) TATA element.

In some embodiments of any of the aspects, the first promoter comprises SEQ ID NO: 08.

In some embodiments of any of the aspects, at least one of the second and third promoters is a HSV-1 or HSV-2 ICP27 promoter operably linked to a tet-O sequence.

In some embodiments of any of the aspects, at least one of the second and third promoters is a HSV-1 or HSV-2 ICP4 promoter operably linked to a tet-O sequence.

In some embodiments of any of the aspects, each of the second and third promoters are the same, and wherein said same promoter is an HSV-1 or HSV-2 promoter selected from the group consisting of: an ICP4 promoter, an ICP27 promoter.

In some embodiments of any of the aspects, each of the second and third promoters are different, and wherein one of these promoters is an HSV-1 or HSV-2 ICP4 promoter, and wherein the other of these promoters is an HSV-1 or HSV-2 ICP27 promoter.

In one aspect of any of the embodiments, described herein is a replication defective HSV recombinant virus, comprising a modified HSV-1 or HSV-2 ICP0 promoter comprising a human cytomegalovirus (hCMV) TATA element, wherein said modified promoter is operably linked to a transgene.

In some embodiments of any of the aspects, the transgene encodes HSV-2 glycoprotein B (gB).

In some embodiments of any of the aspects, said modified promoter comprises SEQ ID NO: 08.

In one aspect of any of the embodiments, described herein is a vaccine comprising the recombinant virus of any one of claims 1-32 in unit dose form.

In one aspect of any of the embodiments, described herein is a method of immunizing a subject against HSV-1 or HSV-2 infection, comprising administering to said subject the vaccine of claim 33.

In some embodiments of any of the aspects, said subject is seropositive for HSV-1.

In some embodiments of any of the aspects, said subject is seropositive for HSV-2.

In some embodiments of any of the aspects, said subject is seronegative for HSV-1 and HSV-2.

In one aspect of any of the embodiments, described herein is a method for producing the virus of any one of claims 1-32, the method comprising; a) infecting complementing cells with the virus, wherein the complementing cells express a functional gene product or products that are needed for replication of the virus and for which sequences encoding such are lacking from the virus genome; b) culturing the complementing cells such that the virus replicates; and c) harvesting said replicated virus from the complementing cells.

In some embodiments of any of the aspects, the complementary cells further express TetR.

In some embodiments of any of the aspects, the complementary cells express ICP0 functional gene product.

In some embodiments of any of the aspects, the complementary cells express UL19 (VP5) functional gene product.

In one aspect of any of the embodiments, described herein is a composition comprising a vaccine comprising the recombinant virus of any of claims 1-32 for use in unit dose form in the treatment of an infection with HSV-1 or HSV-2.

In one aspect of any of the embodiments, described herein is a composition comprising a virus for use in the treatment of an infection with HSV-1 or HSV-2, the composition comprising; a) infecting complementing cells with the virus, wherein the complementing cells express a functional gene product or products that are needed for replication of the virus and for which sequences encoding such are lacking from the virus genome; b) culturing the complementing cells such that the virus replicates; and c) harvesting said replicated virus from the complementing cells.

Definitions

As described above, the genome of the HSV-2 virus according to the invention has a first coding sequence which codes for gB2 and which is operably linked to a first promoter (e.g. an HSV-1 or HSV-2 immediate early promoter) that is under the control of (operably linked to) a first tetracycline operator (tet-O) nucleotide segment. The genome also includes two sequences encoding HSV-2 gD (gD2), a “second coding sequence” and a “third coding sequence”. In one embodiment, at least one sequence encoding HSV-2 gD2 is operably linked to a promoter under control of a tet-O nucleotide segment. In one embodiment, the second coding sequence is operably linked to a second promoter under the control of a second tet-O nucleotide segment and the third coding sequence is operably linked to a third promoter under the control of a third tet-O nucleotide segment.

In one embodiment of various aspects, in order to control viral replication, the genome comprises a fourth coding sequence and that codes for a dominant negative mutant HSV-1 or HSV-2 UL9 protein. In some embodiment, there is also a fifth coding sequence that codes for a dominant negative mutant HSV-1 or HSV-2 UL9 protein. In some embodiments, the dominant negative mutant of the fourth and/or fifth sequence is UL9-C535C. When this sequence is expressed, the mutant protein produced acts in trans to inhibit the replication of HSV-2. The fourth coding sequence is operably linked to a fourth promoter, and this is operably linked to a fourth tet-O sequence. A second copy of a dominant negative mutant HSV-1 or HSV-2 UL9 protein (a “fifth coding sequence,” e.g., UL9-C535C) may also be present and is operably linked to a fifth promoter under the control of a fifth tet-O nucleotide segment.

In certain embodiments of various aspects, in order to control viral replication, the genome of the HSV-2 recombinant virus lacks the sequence encoding the essential UL19 (VP5) protein. In such embodiments, it is not necessary to have a dominant negative UL9 protein for replication incompetency.

Each of the tet operators allows transcription to proceed from its associated promoter when free of tet repressor (tetR) but represses transcription when bound by repressor.

In addition, the genome of the virus is characterized by the absence of a sequence encoding a functional ICP0 protein.

In order to enhance its antigenicity, the genome may in certain embodiments also express recombinant immunomodulating genes, such as IL-12, IL-15 or may express other HSV-1 or HSV-2 major antigens in levels comparable to, or higher than, the levels expressed by wild type HSV-1 or HSV-2 viruses.

The genome of the HSV-2 virus according to the invention lacks a sequence encoding a functional ICP0 protein. In certain embodiments, the second and third coding sequences (encoding HSV-2 gD, also referred to as gD2 herein) are inserted into the position where ICP0 genes are present in wild-type HSV-2, therewith disrupting the ICP0 genes (e.g. as in FIGS. 2 and 3 herein, see also e.g. U.S. Pat. No. 8,809,047 for a description of such embodiments, incorporated by reference herein).

In some embodiments of various aspects, the genome of the HSV-2 virus according to the invention also lacks a sequence encoding a functional UL19 protein. In certain embodiments, the second and/or third coding sequences are inserted at the UL19 locus. In certain embodiments, the second and/or third coding sequences are inserted at the UL26/UL27 intergenic region. Insertion of a coding sequence into an intergenic region of the HSV genome, e.g., UL26 and UL27 intergenic region, does not disrupt or delete other HSV genes; this is an advantageous strategy.

In certain embodiments of various aspects, gD2 is in a bidirectional expression cassette, e.g. with UL9-C535C (e.g. as in FIG. 2 herein), as for instance described in more detail in U.S. Pat. No. 8,809,047, incorporated by reference herein.

In certain embodiments of various aspects, gD2 is in a one-directional expression cassette, e.g. positioned at the UL19 locus, or at the UL26/UL27 intergenic region. In certain embodiments, one gD2 expression cassette is positioned at the UL19 locus and another gD2 expression cassette is positioned at the UL26/UL27 intergenic region, and preferably the nucleotide sequences of these two gD2 expression cassettes are different, while the gD2 protein sequences encoded by these two expression cassettes may be different but preferably are the same.

As used herein, the term “operably linked” refers to genetic elements that are joined together in a manner that enables them to carry out their normal functions. For example, a gene is operably linked to a promoter when its transcription is under the control of the promoter and this transcription results in the production of the product normally encoded by the gene. A tet operator sequence is operably linked to a promoter when the operator blocks transcription from the promoter in the presence of bound tet repressor but allows transcription in the absence of the repressor. The term “recombinant” refers to a virus that has nucleic acid sequences that are the result of recombining nucleic acid sequences and sequence elements and introducing these recombined sequences into the wildtype virus or into a recombinant ancestor virus.

In certain embodiments of various aspects, the first coding sequence of HSV-2 gB (also referred to as gB2 herein) is a codon optimized sequence. For the purposes of the present invention, a “codon optimized”, or “codon diversified” sequence is one in which one or more codons in the wild type sequence are replaced with an alternative codon that codes for the same amino acid and that results in increased protein production. In a preferred embodiment, the nucleic acid encoding HSV-2 gB2 is codon optimized for expression in mammalian cells, preferably human cells. Methods of codon-optimization are known and have been described previously (e.g. WO 96/09378). A sequence is considered codon optimized if at least one non-preferred codon as compared to a wild type sequence is replaced by a codon that is more preferred. Herein, a non-preferred codon is a codon that is used less frequently in an organism than another codon coding for the same amino acid, and a codon that is more preferred is a codon that is used more frequently in an organism than a non-preferred codon. The frequency of codon usage for a specific organism can be found in codon frequency tables, such as in http://www.kazusa.or.jp/codon. Preferably more than one non-preferred codon, e.g. more than 10%, 40%, 60%, 80% of non-preferred codons, preferably most (e.g. at least 90%) or all non-preferred codons, are replaced by codons that are more preferred. Preferably the most frequently used codons in an organism are used in a codon-optimized sequence. Replacement by preferred codons generally leads to higher expression. A non-limiting example of a codon-optimized sequence for HSV2 gB2 is provided herein in SEQ ID NO: 07. Optionally other coding sequences, e.g. one or more of the gD2 coding sequences, may also be codon-optimized.

In one embodiment of various aspects, at least one of the first, second and third promoters are HSV-1 or HSV-2 immediate early promoters. ICP0 and ICP4 promoters are particularly preferred. In one embodiment, each of the first, second and third promoters are HSV-1 or HSV-2 immediate early promoters, e.g. ICP0 and ICP4. In certain embodiments, the second and third promoters operably linked to HSV-2 gD are tetO-containing ICP4 promoters. In certain embodiments of various aspects, at least one of the second and third promoters operably linked to HSV-2 gD2 is a tetO-containing HSV ICP27 promoter.

In one embodiment of various aspects, the first promoter, second promotor, or third promoter are a human cytomegalovirus (hCMV) immediate early promoter.

In embodiments of various aspects where the fourth coding sequence is present, this fourth coding sequence preferably encodes UL9-C535C. In a further embodiment, the fifth coding sequence is present and encodes UL9-C535C. As with the other coding sequences, the fourth and fifth coding sequences may be operably linked to an HSV-1 or HSV-2 immediate early promoter, but in these cases, hCMV immediate early promoters are most preferred.

In one aspect, the replication defective HSV-2 of the invention does not comprise a dominant negative UL9 mutant and is rendered replication incompetent by deletion of the essential expression of UL19, i.e. the replication defective HSV-2 does not express functional UL19 (VP5), does not express functional ICP0, and does not express functional gG2. In one embodiment of this aspect, recombinant gD2 is located in a one directional expression cassette and positioned at the UL19 locus and/or positioned in the UL26/27 intergenic region. In another embodiment, recombinant gD2 is located in a first one directional expression cassette positioned at the UL19 locus and in a second one directional expression cassette positioned in the UL26/27 intergenic region. In yet another embodiment, recombinant gD2 is located in a first one directional expression cassette positioned at the UL19 locus and is operably linked to a first promoter, wherein said first promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a first tet-O sequence, and recombinant gD2 is located in a second one directional expression cassette positioned in the UL26/27 intergenic region and is operably linked to a second promoter, wherein said second promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a second tet-O sequence.

In another embodiment of this aspect, at least one of the second and third promoters that are operably linked to gD2 in a tetO-containing HSV-1 or HSV-2 ICP27 promoter. In one embodiment both the second and the third promoter are a tetO-containing HSV-1 or HSV-2 ICP27 promoter.

In one embodiment of various aspects, the first coding sequence is operably linked to an ICP0 promoter which may optionally be modified so that the TATA element normally present (TATAAGTT (SEQ ID NO: 12)) corresponds to the hCMV TATA element (TATATAAG (SEQ ID NO: 13)), the second and third coding sequences are operably linked to ICP4 promoters, and the fourth and fifth (if present) coding sequences are operably linked to hCMV immediate early promoters, and each promoter is operably linked to a tetO sequence.

In order to obtain optimal results, the promoters used should have a TATA element and the tet operator sequences linked to the promoters should preferably have two op2 repressor binding sequences. The positioning of the operator sequence is important in achieving effective control over the promoter. Specifically, the first nucleotide in the operator sequence is located between six and twenty-four nucleotides 3′ to the last nucleotide in the TATA element (see e.g., U.S. Pat. No. 6,444,871 or 5,972,650). Structural sequences encoding, for example gB2, gD2 or UL9-C535C, are positioned 3′ to the operator.

Accordingly, in certain embodiments of various aspects, a) the first, second, third, and optionally the fourth and fifth promoters of the replication-defective dominant negative HSV-2 virus each have a TATA element; b) each of the first, second, third, and optional fourth and fifth tet-O sequences comprise two op2 repressor binding sites, wherein the first nucleotide in said tet operator is between 6 and 24 nucleotides 3′ to the last nucleotide in said TATA element; c) the first sequence, encoding HSV-2 gB, lies 3′ to said first tet-O sequence, and said first tet-O sequence is operably linked to said first promoter; d) the second sequence, encoding HSV-2 gD, lies 3′ to the second tet-O sequence and said second tet-O sequence is operably linked to the second promoter; e) the third sequence, encoding HSV-2 gD, lies 3′ to said third tet-O sequence and said third tet-O sequence is operably linked to the third promoter; and in some embodiments, f) a fourth sequence, encoding a dominant negative mutant HSV-1 or HSV-2 UL9 protein, lies 3′ to said fourth tet-O sequence and the fourth tet-0 sequence is operably linked to said fourth promoter; and, in some embodiments, a fifth sequence, encoding a dominant negative mutant HSV-1 or HSV-2 UL9 protein, lies 3′ to said fifth tet-O sequence, and said fifth tet-O sequence is operably linked to said fifth promoter.

In one specific aspect of the invention, a replication-defective HSV-2 recombinant virus, is provided that comprises within its genome: (a) a first coding sequence, comprising a codon optimized HSV-2 gB2 sequence operably linked to a first promoter, wherein said first promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a first tet-O sequence and wherein said first coding sequence is preferably displaces the gG2 gene; (b) a second coding sequence, comprising a codon-optimized HSV gD2 sequence operably linked to a second promoter, wherein said second promoter is an HSV-1 ICP4 promoter that is operably linked to a second tet-O sequence and wherein said second coding sequence is located at the UL26/UL27 intergenic region; (c) a third coding sequence, comprising a codon-diversified HSV gD2 sequence operably linked to a third promoter, wherein said third promoter is an HSV-1 ICP27 promoter or an HSV-1 ICP4 promoter that is operably linked to a third tet-O sequence, wherein the third coding sequence displaces the UL19 gene; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein, and does not comprise a sequence encoding HSV-2 gG2 protein.

In one specific aspect, a replication-defective, dominant-negative HSV-2 recombinant virus, is provided that comprises within its genome: (a) a first coding sequence, comprising a codon optimized HSV-2 gB2 sequence operably linked to a first promoter, wherein said first promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a first tet-O sequence; (b) a second coding sequence, comprising an HSV-2 gD2 sequence operably linked to a second promoter, wherein said second promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a second tet-O sequence; (c) a third coding sequence, comprising an HSV-2 gD2 sequence operably linked to a third promoter, wherein said third promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that is operably linked to a third tet-O sequence; (d) a fourth coding sequence, encoding a UL9-C535C protein, and operably linked to a fourth promoter, wherein said fourth promoter is an hCMV immediate early promoter that is operably linked to a fourth tet-O sequence; (d) a fifth sequence, encoding a UL9-C535C protein, and operably linked to a fifth promoter, wherein said fifth promoter is an hCMV immediate early promoter that is operably linked to a fifth tet-O sequence; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein. In certain embodiments, i) said first, second, third, fourth and fifth promoters each have a TATA element; ii) each of said first, second, third, fourth and fifth tet-O sequences comprise two op2 repressor binding sites, wherein the first nucleotide in said tet operator is between 6 and 24 nucleotides 3′ to the last nucleotide in said TATA element; and iii) said first, second, third, fourth and fifth coding sequences each lie 3′ to their respective tet-O sequences, and said tet-O sequences are operably linked to their respective promoters.

In another aspect of the invention, a replication defective HSV recombinant virus (e.g. HSV-1 or HSV-2) is provided that comprises a modified HSV-1 or HSV-2 ICP0 promoter comprising a hCMV TATA element, wherein said modified promoter is operably linked to a transgene. In one embodiment, the modified promoter comprises SEQ ID NO: 08. In one embodiment, the transgene encodes HSV-2 glycoprotein B (gB2). Replication-defective genomic HSV vectors are known in the art and are described in, e.g., Burton et al, Current Opinion in Molecular Therapeutics 7(4):326-336 (2005); Mundle et al. PLoS ONE 8(2): e57224, (2013); Akhrameyeva et al. J. Virol. 85(10): 5036-5047 (2011); and Johnston et al., Vaccine 32 (14):1553-1560 (2014). Such recombinant viruses may be used in both vaccine applications and in gene therapy applications to express a transgene of interest.

In still another aspect, the invention is directed to a vaccine that can be used prophylactically or therapeutically against HSV-2 infection and which comprises one or more of the recombinant viruses described above in unit dose form. The term “unit dose form” refers to a single drug administration entity, e.g., as a syringe, tablet, or capsule. Preferably the “unit dose form” will be a solution in which the drug (e.g., a vaccine virus described herein) is suspended at a concentration that provides a therapeutic or prophylactic effect when a selected volume (unit dose) is administered to a patient by injection and will be found within an injection vial. It is believed that the minimum effective dose in a human should be between about 1×10⁶ and 1×10⁸ plaque-forming units (PFU). Thus, a unit dose should have at least this amount of virus, with 1×10⁶-1×10⁹ PFU or 1×10⁷-1×10⁹ PFU being typical. Vaccines may be stored in a lyophilized form and reconstituted in a pharmaceutically acceptable carrier prior to administration. Alternatively, preparations may be stored in the vehicle itself. The volume of a single dose of the vaccine will vary but, in general, should be between about 0.1 mL and 10 mL and, more typically, between about 0.2 mL and 5 mL, e.g., about 0.5 mL, 1 mL or 2 mL.

The invention also includes methods of immunizing subjects against HSV-1 or HSV-2 infection and the conditions resulting from such infection (e.g., genital herpes ulcers) by administering to the subjects the vaccines described above. The vaccines may also be given to patients that have been infected to prevent or reduce outbreaks of the virus. Any method for administering a vaccine to a patient which does not result in the destruction of vaccine virus is compatible with the present invention. Generally, administration will be by parenteral means such as by intramuscular or intradermal injection. The dosage and scheduling of administration of vaccines can be determined using methods that are routine in the art. The preparations may be administered in either single or multiple injections.

In another aspect, the invention relates to a method for producing any of the viruses described herein comprising: (a) infecting complementing cells with the virus, wherein the complementing cells express a functional gene product or products that are needed for replication of the virus and for which sequences encoding such are lacking from the virus genome; (b) culturing the complementing cells such that the virus replicates; and (c) harvesting said replicated virus from the complementing cells.

In one embodiment, the complementing cells further express a tetR to repress expression from the tetO-regulated promoters. In certain embodiments, the complementing cells express at least one functional gene product selected from ICP0, UL9, or UL19 (VP5). In certain embodiments, the complementing cells express tetR and ICP0. In certain embodiments, the complementing cells express tetR, ICP0 and UL19 (VP5).

As used herein, a “functional gene product or products that are needed for replication of the virus” refers to any gene product or products required for, e.g., the genetic replication of the virus in a host cell. These gene product(s) include, but are not limited to, gene products required for transcription of immediate-early, early, or late gene products (e.g., α-TIF); immediate-early, early, or late gene products; gene products required for virion host shutoff (e.g., VHS, and UL41); and gene products required for production of, e.g., the capsid, viral envelope, or viral surface receptors. One skilled in the art will be able to determine those gene product(s) required for replication of the viruses described herein.

As used herein, a “subject” means a human or animal. In one embodiment, the animal is a vertebrate such as a primate, rodent, domestic animal, or game animal. In one embodiment, the subject is human. The terms, “patient”, “individual” and “subject” are used interchangeably herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of an HSV-2 gG2 locus-specific vector sequences plus a tetO-bearing HSV-1 ICP0 promoter sequence modified to replace the ICP0 TATA element with the hCMV TATA element. The elements are presented as follows along the sequence: the sequence from −900 to −2 bp upstream of the gG2 open reading frame (black box); the poly A signal sequence of HSV-1 ICP27 (gray box); the tetO-bearing modified HSV-1 ICP0 promoter plus part of 5′ untranslated region of ICP0 gene (striped box), a sequence containing multiple cloning sites (open box), and the sequence from +1 to +900 bp downstream of the gG2 ORF stop codon (black box).

FIG. 2 is a schematic of genomes of non-replicating dominant-negative HSV-2 recombinant viral vaccine construct, CJ2-gD2, and a CJ2-gD2-derived viral recombinant, CJ2-gD2/gB2(UL9). UL and US represent the unique long and unique short regions of the HSV-2 genome, respectively, which are flanked by their corresponding inverted repeat regions (open boxes). The replacements of both copies of the ICP0 coding sequences with DNA sequences encoding UL9-C535C under control of the tetO-bearing hCMV major immediate-early promoter and gD2 under the tetO-bearing HSV-1 ICP4 promoter in CJ2-gD2 are shown expanded above the ICP0 coding sequences of the HSV-2 genome. The replacement of the HSV-2 UL9 DNA sequence encoding UL9 amino acids 285-742 with DNA sequence encoding gB2 under control of the tetO-bearing hCMV major immediate-early promoter is shown expanded below the UL9 coding sequences of the HSV-2 genome.

FIG. 3 is a schematic drawing of the genome of a non-replicating dominant-negative HSV-2 recombinant viral vaccine construct, named CJ2-gD2/gB2, in which the HSV-2 gG2 coding sequence in CJ2-gD2 is replaced with a codon-optimized gB2 sequence under control of the tetO-bearing modified HSV-1 ICP0 promoter plus part of 5′ untranslated region of ICP0 gene described in FIG. 21. Again, the replacements of both copies of the ICP0 coding sequences with DNA sequences encoding UL9-C535C under control of the tetO-bearing hCMV major immediate-early promoter and gD2 under the tetO-bearing HSV-1 ICP4 promoter in CJ2-gD2 are shown expanded above the ICP0 coding sequences of the HSV-2 genome.

FIG. 4 shows the expression of gB2 and gD2, as well as the absence of gG2 expression following infection of Vero cells with CJ2-gD2/gB2. Vero cells in duplicate were either mock-infected or infected with wild-type HSV-2, CJ2-gD2, CJ2-gD2/lacZ, a CJ2-gD2 derived virus that encodes the lacZ gene in the HSV-2 gG2 locus, or CJ2-gD2/gB2 at an MOI of 5 PFU/cell. Infected cell extracts were prepared at 16 h post-infection. Proteins in infected cell extracts were resolved on SDS-PAGE, followed by immunoblotting with monoclonal antibodies against gB2, HSV-1/2 gD, gG2, or ICP27 (HSV-specific input control). In contrast to wild-type HSV-2, which can replicate as early as 6 hours post-infection, CJ2-gD2, CJ2-gD2/lacZ and CJ2-gD2/gB2 do not replicate or amplify genome following infection.

FIG. 5 shows that CJ2-gD2/gB2 expresses gB2 more efficiently than CJ2-gD2/gB2(UL9) in Vero cells. Vero cells in duplicate were either mock-infected or infected with wild-type HSV-2, CJ2-gD2, CJ2-gD2/lacZ, CJ2-gD2/gB2, or CJ2-gD2/gB2(UL9) at an MOI of 5 PFU/cell. Infected cell extracts were prepared at 16 h post-infection. Proteins in infected cell extracts were resolved on SDS-PAGE, followed by immunoblotting with monoclonal antibodies against gB2, HSV-1/2 gD, or ICP27 (HSV-specific input control).

FIG. 6 shows a trans-dominant-negative effect of CJ2-gD2/gB2 on replication of wild-type HSV-2. Vero cells were infected in triplicate with either wild-type HSV-2 strain 186 alone at an MOI of 2 PFU/cell; with wild-type HSV-2 (MOI 2) and N2-lacZ, a HSV-2 ICP0 deletion mutant that does not express UL9-C535C, at an MOI of 5 PFU/cell; with wild-type HSV-2 (MOI 2) and CJ2-gD2 at an MOI of 5 PFU/cell; or with wild-type HSV-2 (MOI 2) and CJ2-gD2/gB2 at an MOI of 5 PFU/cell. Infected cells were harvested at 18 h post-infection and viral titers were determined on Vero cell monolayers. Viral titers are expressed as the mean+/−SD. Number on the top of the graph indicates the fold reduction in wild-type virus yield between single infection and co-infection.

FIG. 7 shows the induction of HSV-2-neutralizing antibody responses. 7- to 8-week-old female BALB/c mice were either immunized with CJ2-gD2/gB2 (n=8) or CJ2-gD2 (n=7) at a dose of 2×10⁶ PFU/mouse (H) or with CJ2-gD2/gB2 (n=8) or CJ2-gD2 (n=8) at a dose of 5×10⁵ PFU/mouse (L). Mice were boosted 2 weeks later with the same vaccine virus at the same dose as used for prime immunization. Blood was obtained from the tail veins of mice 2 weeks after boost immunization. Serum from each immunized animal were heat-inactivated. HSV-2-specific neutralizing antibody titers were determined. The results represent average titers ±SEM (SEM, un-paired Student's t-tests).

FIGS. 8A-8C present results indicating that CJ2-gD2/gB2 is as effective as CJ2-gD2 in protecting against HSV-2 genital infection and disease. This is unexpected, given that CJ2-gD2/gB2 lacks the antigen gG2. Female BALB/c mice treated as described for FIG. 7 were pre-treated with medroxyprogesterone at 2 weeks post boost immunization followed by intravaginal challenge with 5×10⁵ PFU of HSV-2 strain G 5 days later. (A) Vaginal swabs were taken on days 1, 2, 3, 5, and 7 post-challenge. Infectious virus titers in swab materials were assessed by standard plaque assay on Vero cell monolayers. Viral titers are expressed as the mean±SEM in individual vaginal swabs. (B and C) After challenge with wild-type HSV-2, individual mice were observed during a 21-day follow-up period for the incidence of genital and disseminated HSV-2 disease using the following scale: 0=no sign, 1=slight genital erythema and edema, 2=moderate genital inflammation, 3=purulent genital lesions and/or systemic illness, 4=hind-limb paralysis, and 5=death (B), and percent survival (C).

FIGS. 9A-9C present results showing that immunization with CJ2-gD2/gB2 can elicit durable protective immunity against HSV-2 genital infection and disease, and that this occurs even in the absence of gG2. Seven to eight week old female BALB/c mice were either sham-immunized (n=8) or immunized with CJ2-gD2/gB2 (n=8) at a dose of 1×10⁶ PFU/mouse as described earlier. Mice were boosted with the same dose of CJ2-gD2/gB2 on days 14 and 28 post primary immunization. Five months after the third immunization, mice were challenged intravaginally with HSV-2 strain G at 5×10⁵ PFU/mouse. (A) Vaginal swabs were taken on days 1, 2, 3, 5, and 7 post-challenge. Infectious viruses in swab materials were assessed by standard plaque assay on Vero cell monolayers. Viral titers are expressed as the mean±SEM in individual vaginal swabs. (B and C) After challenge with wild-type HSV-2, individual mice were observed during a 21-day follow-up period for the incidence of genital and disseminated HSV-2 disease (using a scale described in FIG. 8) (B) and percent survival (C).

FIG. 10 shows the induction of HSV-1-neutralizing antibody responses. 7- to 8-week-old female BALB/c mice were immunized with CJ2-gD2/gB2 at a dose of 2×10⁶ PFU/mouse (n=7). Individual groups of mice were boosted with CJ2-gD2/gB2 at the same dose 2 weeks later. Blood was obtained from the tail veins of mice 2 weeks after primary immunization (gray bar) as wells as 2 weeks after boost immunization (black bar). Heat-inactivated serum from each CJ2-gD2/gB2-immunized mouse after boost immunization was assayed individually for HSV-1-specific neutralizing antibody titers on Vero cell monolayers. Heat-inactivated pooled serum was used for determining HSV-1-specific neutralizing antibody response after primary immunization. The results represent average titers ±SEM.

FIGS. 11A-11C present results indicating that immunization with CJ2-gD2/gB2 can effectively protect mice against HSV-1 genital infection and disease. Female BALB/c mice described for FIG. 10 were pre-treated with medroxyprogesterone at 2 weeks post boost immunization followed by intravaginal challenge with 5×10⁵ PFU of HSV-1 strain mP 5 days later. (A) Vaginal swabs were taken on days 1, 2, 3, 5, and 7 post-challenge. Infectious virus titers in swab materials were assessed by standard plaque assay on Vero cell monolayers. Viral titers are expressed as the mean±SEM in individual vaginal swabs. (B and C) After challenge with wild-type HSV-1, individual mice were observed during a 21-day follow-up period for the incidence of genital and disseminated HSV-1 disease (using scale in FIG. 8) (B) and percent survival (C).

FIG. 12 presents results indicating that CJ2-gD2/gB2 is significantly more effective than gD2-alum/MPL subunit vaccine in eliciting an HSV-2-specific neutralizing antibody response in immunized guinea pigs. Female Hartley guinea pigs were randomly assigned to three groups of six animals each in the first experimental group and three groups of six to eight each in the second experimental group. They were either immunized with 5 μg of purified recombinant gD2 freshly formulated with 12.5 μg of MPL and 125 μg of alum or immunized with CJ2-gD2/gB2 at a dose of 5×10⁶ PFU on days 0, 14, and 28. Blood was taken at 2 weeks after the first, second, and third immunizations. Heat inactivated serum from each animal was assayed individually for HSV-2-specific neutralizing antibody titers on Vero cell monolayers. The results represent average titers ±SEM.

FIGS. 13A and 13B present results demonstrating that CJ2-gD2/gB2 is significantly superior to gD2-alum/MPL subunit vaccine in protecting against intravaginal wild-type HSV-2 infection in guinea pigs. Female guinea pigs sham-immunized with DMEM or immunized with gD2-alum/MPL or CJ2-gD2/gB2 described in FIG. 12 were challenged intravaginally with 5×10⁵ PFU of HSV-2 strain MS. Vaginal swabs were taken on days 1, 2, 3, 5, 7, and 9 post-challenge. Infectious virus on swab materials was determined by standard plaque assay in Vero cells. Viral yields are expressed as the means±SEM for individual swabs (A). The duration of viral shedding is represented as the mean number of days during which infectious virus was detected in vaginal swabs ±SEM (B). Statistical method (SEM, un-paired Student's t-tests) used for comparisons. P-value equal to or greater than 0.05 is significant.

FIGS. 14A-14C present results indicating that immunization with CJ2-gD2/gB2 can provide a full protection against primary HSV-2 genital disease in guinea pigs. Sham-immunized, gD2-alum/MPL- or CJ2-gD2/gB2-immunized guinea pigs described in FIG. 13 were monitored daily during the first 21-day follow-up period for the incidence of genital and disseminated HSV-2 disease. The severity of disease was scored as follows: 0, no sign of disease; 1, redness or swelling; 2, a few small vesicles; 3, several large vesicles; 4, several large ulcers with maceration; 5, paralysis; and 6, death. Presented are the average disease scores for the first 21 days after challenge (A), the percent of animals that experienced primary herpetic disease (B), and the percent of survival until day 60 after challenge (C).

FIGS. 15A-C present results showing that immunization with CJ2-gD2/gB2 is highly effective in protecting against recurrent HSV-2 disease in guinea pigs. After challenge with wild-type HSV-2, individual guinea pigs described in the legend of FIG. 13 were monitored daily from days 21 to 60 post challenge for the incidence of recurrent genital and disseminated HSV-2 disease. Presented are the cumulative numbers of recurrent lesions per animal (A), average number of days that recurrent disease was experienced per animal (B), and the percent of animals that experienced recurrent disease between days 21 to 60 after challenge (C). Statistical method (SEM, un-paired Student's t-tests) used for comparisons. P-value equal to or greater than 0.05 is significant.

FIGS. 16A and 16B present results showing that intravaginal infection of guinea pigs with wild-type HSV-2 strain MS, wp/28 (displayed per two groups assigned for subsequent immunization as described in FIG. 17). Twenty-eight female Hartley guinea pigs were challenged with 5×10⁵ PFU of HSV-2 strain MS/wp28. The intra-vaginal mucosae were swabbed on day 2 and 5 post infection and clinical symptoms were examined daily until day 70 post-challenge. (A) Mean infectious titers of swab samples at day 2 and 5 post infection, respectively, where the error bars represent the standard deviations (SD), (B) Mean clinical scores from day 1 to day 20 after challenge (before prime immunization at day 21).

FIG. 17 presents results showing that CJ2-gD2/gB2 immunization induced HSV-2-specific neutralizing antibody responses in immunized guinea pigs. On day 21 post-intravaginal infection, 27 surviving animals were divided into 2 groups based on the disease scores as well as titers of virus shedding on days 2 and 5. Animals in group 1 (n=13, gray bars) were sham-immunized with DMEM, while animals in group 2 (n=14, black bars) were immunized with CJ2-gD2/gB2 at a dose of 5×10⁶ PFU/animal. Blood samples were obtained from the saphenous veins on day 21 post-intravaginal infection and 14 days after primary immunization (day 35) and 14 days after boost immunization (day 49). Data represents the mean HSV-2-specific neutralizing antibody titers in corresponding groups where error bars represent the standard deviations.

FIGS. 18A and 18B present results showing that CJ2-gD2/gB2 immunization effectively protects guinea pigs against recurrent genital disease. Recurrent genital skin lesions were monitored during days 21 to 70 post-intravaginal infection. (A) Data represent the percentage of animals experiencing recurrent disease in each group. (B) percent of animal experiencing recurrent disease.

FIGS. 19A and 19B present results showing that CJ2-gD2/gB2 immunization effectively reduced recurrent genital lesions in guinea pigs. Animals' recurrent genital skin lesions were monitored daily during day 21 to 70 post-intravaginal infection. (A) Mean cumulative numbers of recurrent lesions per animal. (B) Mean frequency (days) of animal experiencing recurrent genital disease, where error bars represent the standard deviations.

FIGS. 20A and 20B present results showing that CJ2-gD2/gB2 immunization effectively reduced recurrent viral shedding. Animals' intra-vaginal mucosae were swabbed daily from day 27 to 52 post-intravaginal infection. HSV-2 viral DNA copies in swabbing samples were detected by Real-time PCR analysis. (A) Percentage of the animals that experienced recurrent virus shedding within each group. (B) Mean cumulative days of recurrent viral shedding per animal within each group, where error bars represent the standard deviations.

FIG. 21 shows a schematic of QF-VAC, an exemplary replication incompetent HSV, made incompetent by essential gene deletion. The replication incompetent HSV is a UL19 (VP5) deletion mutant comprising 1 of 2 recombinant copies of gD2 under tetO-containing HSV-1 ICP27 promoter at the UL19 locus; and the second copy of recombinant gD2 in a one directional expression cassette in a UL26/UL27 intergenic region. The replication incompetent HSV is an ICP0 and a gG2 deletion mutant with two copies of gD2 under tetO-containing immediate-early promotes (and at least one copy is under tet-O)-containing HSV-1 ICP4 promoter. The gG2 gene is replaced by the codon-optimized gB2 gene under the control of the tetO-bearing HSV-1 ICP0 promoter, as described in FIG. 3 legend.

FIG. 22 shows results demonstrating that immunization with purified CJ2-gD2/gB2 induces HSV-2-neutralizing antibody titers comparable to responses induced by crude CJ2-gD2/gB2 (clarified cell lysate). Groups of 7- to 8-week-old female Balb/cAnNCrl mice (n=8 each) were either immunized with purified or crude CJ2-gD2/gB2 at the doses indicated. Mice were boosted 2 weeks later with the same vaccine virus at the same dose as used for prime immunization. Blood was obtained from the saphenous vein of mice 20 days after boost immunization. Serum from each immunized animal was heat-inactivated and HSV-2-specific neutralizing antibody titers were determined. HSV-2 neutralizing antibody titers (IC50) are shown for individual mice (dots), group medians are indicated with a solid line. P values of vaccine groups versus formulation buffer are indicated, when significant. The dotted line indicates the estimated lower limit of detection (LLoQ) of the assay used.

FIGS. 23A and 23B present results indicating that purified CJ2-gD2/gB2 is as effective as crude CJ2-gD2/gB2 in protecting against HSV-2 genital disease. Female Balb/cAnNCrl mice were intra-muscularly either sham-immunized with formulation buffer (black solid line, in clinical score [CS] graph with additional triangular point markers) or immunized with purified CJ2-gD2/gB2 at a dose of 1.8×10⁵ (grey dotted line, with squares for CS), 1.8×10⁶ (black dotted line, with squares for CS) or 1.8×10⁷ PFU (black dashed line, with squares for CS) or crude CJ2-gD2/gB2 at 1.43×10⁶ PFU/mouse (grey solid line, with circles for CS). Individual groups of mice were boosted with the same vaccine virus and at the same dose 2 weeks later. Mice were pre-treated with medroxyprogesterone at 2 weeks post boost immunization followed by intravaginal challenge with 5×10⁵ PFU of HSV-2 strain G 5 days later. After challenge with wild-type HSV-2, individual mice were observed during a 21-day follow-up period (A) for the incidence of genital and disseminated HSV-2 disease using the following clinical score scale: 0=no sign, 1=slight genital erythema and edema, 2=moderate genital inflammation, 3=purulent genital lesions and/or systemic illness, and 4=hind-limb paralysis, and (B) for percent survival.

FIG. 24 presents results indicating that purified CJ2-gD2/gB2 is as effective as crude CJ2-gD2/gB2 in reducing vaginal virus shedding, i.e. protecting mice against HSV-2 genital infection. Female Balb/cAnNCrl mice treated and challenged as described for FIG. 23. On days 1, 2, 4, and 7 post-challenge, vaginal mucosae were swabbed with calcium alginate to assess viral shedding. HSV-2 virus titers of individual mice vaginal swabs are shown as dots, group means are indicated with a solid line. When compared with the sham immunization group, vaccine immunized groups showed significant decrease in virus shedding titers in day 1, 2 and 4 post challenge swabs. No significant differences in shedding titers were observed between groups on day 7.

FIG. 25 shows that CJ2-gD2/gB2 induces T cell responses (IFNγ+) against gB2, gD2 and other vaccine components. ELISPOT counts (SFU per 10⁶ splenocytes) for individual mice immunized with purified CJ2-gD2/gB2 vaccine are presented by dots and group geometric means are indicated with a solid line. IFNγ release was detected after stimulation with the gD2 peptide pool and gB2 peptide pool #1. Culture medium (negative control) and PMA (positive control, data not shown) gave negative and positive IFNγ response, respectively. In addition, ICP27 and VP11/12 peptides showed positive responses. Responses of mice receiving formulation buffer were all below the limit of detection (LOD) (data not shown).

DETAILED DESCRIPTION OF THE INVENTION

The present invention makes use of the concept of using tetracycline gene-switch technology together with essential gene deletions and/or a dominant-negative mutant polypeptide of HSV-1 UL9 to develop an HSV recombinant virus which is replication-incompetent and capable of inhibiting wild-type HSV infections. The methods described herein may be used to make vectors that recombinantly express two sequences encoding HSV-2 gD2 and, at least one sequence encoding gB2.

The Tet Operator/Repressor Switch and Recombinant DNA

Methods for making recombinant DNA molecules with genes whose expression is regulated by the tetracycline operator and repressor protein have been previously described (see U.S. Pat. Nos. 6,444,871; 6,251,640; and 5,972,650) and plasmids which contain the tetracycline-inducible transcription switch are commercially available (T-REx™, Invitrogen, Calif.).

An essential feature of the DNA of the present invention is the presence of genes that are operably linked to a promoter, preferably having a TATA element. A tet operator sequence is located between 6 and 24 nucleotides 3′ to the last nucleotide in the TATA element of the promoter and 5′ to the gene. Virus may be grown in cells that express the tet repressor to block gene transcription and allow viral replication. The effectiveness of the tet repressor in blocking gene expression from the tetO sequence-containing promoter is enhanced by using a form of operator which contains two op2 elements each having the nucleotide sequence: TCCCTATCAGTGATAGAGA (SEQ ID NO: 11) linked by a sequence of, preferably, 1-3 nucleotides. When repressor is bound to this operator, very little or no transcription of the associated gene will occur. If DNA with these characteristics is present in a cell that also expresses the tetracycline repressor, transcription of the gene that can prevent viral infection and that is operably linked to the tet operator sequence (e.g., a dominant negative mutant such as UL9-C535C) will be blocked by the repressor binding to the operator and e.g. replication of the virus will occur.

Selection of Promoters and Genes

During productive infection, HSV gene expression falls into three major classes based on the temporal order of expression: immediate-early (α), early (β), and late (γ), with late genes being further divided into two groups, γ1 and γ2. The expression of immediate-early genes does not require de novo viral protein synthesis and is activated by the virion-associated protein VP16 together with cellular transcription factors when the viral DNA enters the nucleus. The protein products of the immediate-early genes are designated infected cell polypeptides ICP0, ICP4, ICP22, ICP27, and ICP47 and it is the promoters of these genes that are preferably used in directing the expression of the recombinant genes discussed herein.

ICP0 plays a major role in enhancing the reactivation of HSV from latency and confers a significant growth advantage on the virus at low multiplicities of infection. ICP4 is the major transcriptional regulatory protein of HSV, which activates the expression of viral early and late genes. ICP27 is essential for productive viral infection and is required for efficient viral DNA replication and the optimal expression of viral γ genes and a subset of viral 13 genes. The function of ICP47 during HSV infection appears to be to down-regulate the expression of the major histocompatibility complex (MHC) class I on the surface of infected cells.

The HSV-1 UL9-C535C sequence consists of UL9 amino acids 1-10, a Thr-Met-Gly tripeptide, and amino acids 535 to 851 of UL9 (Yao, et al., Hum. Gene Ther. 10:419-27 (1999)). An example of a sequence coding for UL9-C535C is provided in SEQ ID NO: 14. The other sequences described for use in recombinant viruses are all well known in the art. For example, the full length genomic sequence for HSV-1 may be found as GenBank sequence X14112. The HSV-1 ICP4 sequence may be found as GenBank number X06461; HSV-1 glycoprotein D may be found as GenBank sequence J02217; HSV-2 glycoprotein D may be found as GenBank number K01408; the HSV-1 UL 9 gene as GenBank sequence M19120; and gB2 as GenBank sequence M15118.1. All of these references are incorporated by reference herein in their entirety. Examples of gD2 and gB2 amino acid sequences are provided as SEQ ID NOs: 23 and 24 respectively.

Inclusion of Tet Repressor and Making of Virus

Sequences for the HSV ICP0 and ICP4 promoters and for the genes whose regulation they endogenously control are well known in the art (McGeoch et al., J. Gen. Virol. 72:3057-3075 (1991); McGeoch et al., Nucl. Acid Res. 14:1727-1745 (1986); Perry, et al., J. Gen. Virol. 67:2365-2380 (1986)) and procedures for making viral vectors containing these elements have been previously described (see US 2005/0266564). These promoters are not only very active in promoting gene expression, they are also specifically induced by VP16, a virus-associated transactivator released when HSV-1 or HSV-2 infects a cell.

Once appropriate DNA constructs have been produced, they may be incorporated into HSV-2 virus using methods that are well known in the art (Akhrameyeva, J. Virol. 85:5036-47 (2011); Lu, et al., J. Invest. Dermatol. 129:1174-84 (2009); Yao, et al., Hum. Gene Ther. 10:1811-8 (1999)).

In one embodiment, viruses described herein are replicated using complementing cells. A complementing cell expresses the gene or genes missing in the genome of a replication-defective virus (e.g., ICP0 and VP5), and are commonly used to propagate replication-defective viruses. Complementary cells are further reviewed in Dudek and Knipe. Virology 2006 January; 344(1): 230-239. One skilled in the art will be capable of determining the appropriate complementary cell for use in replicating a given virus described herein. Preferably, the complementary cell further expresses TetR in order to repress expression from the TetO-regulated promoters. In one embodiment, the complementing cells express UL9. In another embodiment, the complementing cells express ICP0 and UL9.

Immunization Methods

The viruses described herein will be used to immunize individuals and/or patients, typically by injection as a vaccine. Other routes of administration, e.g. oral administration, could also be used. The vaccine may be used either prophylactically to prevent HSV-1 or HSV-2 infection or therapeutically to reduce the severity of symptoms if an HSV-1 or HSV-2 infection has already occurred. In order to make a vaccine, the viruses are suspended in a pharmaceutically acceptable solution such as sterile isotonic saline, water, phosphate buffered saline, 1,2-propylene glycol, polyglycols mixed with water, Ringer's solution, etc. The exact number of viruses to be administered is not crucial to the invention but should be an “effective amount,” i.e., an amount sufficient to elicit an immunological response strong enough to inhibit HSV infection. In general, it is expected that the number of viruses (PFU) initially administered will be between 1×10⁷ and 1×10⁹.

The effectiveness of a dosage, as well as the effectiveness of the overall treatment can be assessed using standard immunological methods to test for the presence of antibodies effective at attacking HSV. Immunizing injections or administrations can be repeated as many times as desired. Unless otherwise defined, all terms of art, notations and other scientific terms or terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this invention pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not necessarily be construed to represent a substantial difference over what is generally understood in the art.

The practice of embodiments of the present invention will employ, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry, nucleic acid chemistry, and immunology, which are within the skill of the art. Such techniques are explained fully in the literature, such as, Current Protocols in Immunology (J. E. Coligan et al., eds., 1999, including supplements through 2016); Current Protocols in Molecular Biology (F. M. Ausubel et al., eds., 1987, including supplements through 2016); Short Protocols in Molecular Biology, F. M. Ausubel et al., eds., fifth edition 2002, including supplements through 2016; Molecular Cloning: A Laboratory Manual, third edition (Sambrook and Russel, 2001); PCR: The Polymerase Chain Reaction, (Mullis et al., eds., 1994); The Immunoassay Handbook (D. Wild, ed., Stockton Press NY, 1994); Bioconjugate Techniques (Greg T. Hermanson, ed., Academic Press, 1996); Methods of Immunological Analysis (R. Masseyeff, W. H. Albert, and N. A. Staines, eds., Weinheim: VCH Verlags gesellschaft mbH, 1993), Harlow and Lane Using Antibodies: A Laboratory Manual (Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1999; and Beaucage et al. eds., Current Protocols in Nucleic Acid Chemistry John Wiley & Sons, Inc., New York, 2000, including supplements through 2016).

As used herein the term “herpes simplex virus” (HSV) refers to both HSV type 1 and HSV type 2 (See e.g. Fatahzadeh M1, Schwartz R A. Human herpes simplex virus infections: epidemiology, pathogenesis, symptomatology, diagnosis, and management, J Am Acad Dermatol. 2007 November; 57(5):737-63, ATCC holdings (Manassas, Va. 20110 USA) include a number of HSV-1 and HSV-2 strains, including for example: HSV-1 HF; HSV-1 MacIntyre; HSV-1 KOS; HSV-1 GHSV-UL46; HSV-1 ATCC-2011-9; HSV-2 MS; HSV-2 G; HSV-2 ATCC-2011-2). As used herein, the term “ICP0 protein” refers to the HSV protein that is an immediate-early protein which possesses E3 ubiquitin ligase activity. ICP0 activates HSV-1 gene expression, disrupts nuclear domain (ND) 10 structures, mediates the degradation of cellular proteins, and enables evasion of the host's antiviral defenses. As used herein the term “ICP0 deficient HSV” refers to a recombinant HSV vector whose genome does not encode active ICP0 or fully functional ICP0, i.e. ICP0 with normal wild type function. Activity of ICP0 can be monitored using any of the means known to those in the art (See e.g. Miles C Smith et al, HSV-1 ICP0: paving the way for viral replication Future Virol. 2011 April; 6(4): 421-429; Mirna P Lanfranca et al., HSV-1 ICP0: An E3 Ubiquitin Ligase that counteracts host intrinsic and immunity, Cells 2014 3:438-454).

There are many variants of HSV ICP0 protein, e.g. some of HSV-1 ICP0, strain KOS variants are: Genebank Accession: P08393.1 GI: 124134; Accession: AFI23590.1 GI: 384597746; Accession: AFI23649.1 GI: 384597805; Accession: AFE62827.1 GI: 380776964; Accession: AFE62886.1 GI: 380777023; Accession: ADM22381.1 GI: 304318198; Accession: AL018731.1 GI: 952947655; Accession: AL018672.1 GI: 952947596; Accession: AL018655.1 GI: 952947578; Accession: AL018596.1 GI: 952947519; Accession: AKH80472.1 GI: 822581062; Accession: AKH80399.1 GI: 822580988; Accession: AKG61929.1 GI: 820021112; Accession: AKG61857.1 GI: 820021035; etc. and the like. Each strain of HSV1 or of HSV2 have multiple variants, all with functional ICP0. These variants are well known in the art and can be found in protein databases. Such variants may be used in methods of the invention. Examples of HSV-2 ICP0 variants, include but are not limited to: Accession: YP 009137210: YP 009137210.1 GI:820945210; Accession: YP 009137151.1 GI: 820945151; Accession: AEV91397.2 GI: 556197555; Accession: AEV91338.2 GI: 556197550; Accession: ADG01890.1 GI: 295322885; Accession: ADG01889.1 GI: 295322883; Accession: ADG01888.1 GI: 295322881; Accession: ADG01887.1 GI: 295322879; Accession: ADG01885.1 GI: 295322875; Accession: ADG01886.1 GI: 295322877; etc, and the like.

As used herein, the term “gG2 protein” refers to an antigenic envelope glycoprotein that is specific for HSV-2 virus (See Gorander, S. et al, Glycoprotein G of HSV-2 as a novel vaccine antigen for immunity to genital and neurological disease). The protein has been mapped to the US segment of HSV-2 genome (See Mardsen et al. J. Virol. 1984, 50(2): 547-554 and Roizman et al. Virology, 1984, 133: 242-247). gG2 protein is cleaved intracellularly into a membrane bound portion and a secreted portion. Both the membrane bound portion and the secreted portion of gG2 function as antigens (Staffan et al. J. Clin. Microbiol. 2003, 41(8):3681-3686; Staffan et al. Clin. Vaccine Immunol. 2006, 13(6):633-639). The secreted portion of gG2 is also known to modify NGF-TrkA signaling to attract free nerve endings to the site of infection (Cabrera, et al. PLoS Pathog. 2015 January; 11(1): e100457). Alternative names for HSV gG2 protein are: HSV2 gG, HSV2 gG antigen, HSV gG-2 protein, HSV gG 2, Herpes Simplex Virus 2 glycoprotein G protein, HSV-2 gG protein, HSV gG-2.

HSV gG2 gene is also known as US4. The complete nucleotide sequence can be found at GenBank Accession: KF588470. In certain embodiments, gB2 is located at the gG2 (US4) locus of the HSV-2 genome thereby generating a gG2 deficient HSV-2.

As used herein the term “gG2 deficient HSV-2” or “gG2*” refers to a recombinant HSV vector whose genome does not encode active or functional gG2, i.e. gG2 with wild type function, e.g. antigenic function. Serologic antigenic activity of gG2 can be monitored using any of the means known to those in the art (See e.g. Sulaiman et al, Clin Vaccine Immunol. 2009 June; 16(6): 931-934). It should be understood that there are many variants of HSV gG2 protein, all with functional gG2. These variants are well known in the art and can be found in protein databases.

As used herein the term “UL19 deficient HSV-2” or “UL19*” refers to a recombinant HSV vector whose genome does not encode active or functional UL19 open reading frame protein, i.e. VP5 protein with wild type function. VP5 is non-functional if it cannot form HSV-2 viral capsid and therefore virus. VP5 is a major capsid protein of HSV-2. It should be understood that there are many variants of HSV UL19, all with functional VP5. These variants are well known in the art and can be found in protein databases. The genome of HSV-2 and UL19 open reading frame is described, e.g., in J Virol. 1998 March; 72(3): 2010-2021.

As used herein, “displaces” refers to the removal of a gene (e.g., G2, or UL19), or fragment thereof, from its endogenous location in the vector genome by the locatlization of an exogenous sequence (e.g., an indicated coding sequence) into such endogenous location. “Displacing” a gene can result in the depletion of the gene such that a genome no longer encodes the active or functional gene, or hinders the function of the gene.

As used herein, the term “variant” in the context of polypeptides or proteins refers to a polypeptide or protein that comprises an amino acid sequence which has been altered by the introduction of amino acid residue substitutions, deletions and/or additions. Typically, substitutions are conservative amino acid substitutions, however non-conservative substitutions can be made that do not destroy the functionality of the protein, e.g. HSV gB2 or gD2 proteins. “Conservative amino acid substitutions” refers to replacing one amino acid with another having similar structural and/or chemical properties, e.g. such as the replacement of a leucine with an isoleucine or valine, an aspartate with a glutamate, or a threonine with a serine, or glycine with another small amino acid residue. Conservative substitution tables providing functionally similar amino acids are well known in the art. As used herein, the term “non-conservative” refers to substituting an amino acid residue for a different amino acid residue that has different chemical properties. The non-conservative substitutions include, but are not limited to aspartic acid (D) being replaced with glycine (G); asparagine (N) being replaced with lysine (K); or alanine (A) being replaced with arginine (R). For purposes of embodiments of the invention non-conservative substitutions may reduce but does not destroy the proteins normal function.

As used herein the term “comprising” or “comprises” is used in reference to compositions, methods, and respective component(s) thereof, that are essential to the invention, yet open to the inclusion of unspecified elements, whether essential or not.

As used herein the terms, “consisting essentially of,” or variations such as “consists essentially of”, or “consist essentially of” refer to the inclusion of any recited elements, or group of elements, and the optional inclusion of other elements, of similar or different nature than the recited elements, that do not materially change the basic properties of the claimed elements. For example, a nucleotide sequence that consists essentially of a recited sequence may also include additional one or more nucleic acid additions, deletions, or substitutions that do not materially change, by a statistically significant amount, the function of the protein prior to the additions, deletions, or substitutions. For example, substitutions may correlate to the degenerative amino acid code.

The term “consisting of” refers to compositions, methods, and respective components thereof as described herein, which are exclusive of any element not recited in that description of the embodiment. For example, the nucleotide sequence has no additions, deletions or substitutions.

As used herein, the term “protein” or “polypeptide” refers to a polymer or oligomer of consecutive amino acid residues. As used herein, the term “nucleotide sequence” refers to DNA molecule sequences (e.g., cDNA or genomic DNA).

As used herein, the term “promoter” refers to regulatory control nucleic acid sequences involved in transcription of nucleotide coding sequences, which may or may not include enhancer elements. Such a promoter may be inducible or constitutive. The term “operably linked” refers to a juxtaposition wherein the components described are in a relationship permitting them to function in their intended manner. A promoter “operably linked” to a coding sequence is ligated in such a way that expression of the coding sequence is achieved.

Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein should be understood as modified in all instances by the term “about.” The term “about” when used in connection with percentages may mean±10%, or even e.g. ±20%, preferably ±10%, more preferably ±5%, still more preferably ±1%. In addition, the singular terms “a,” “an,” and “the” include plural referents unless context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise. It is further to be understood that all base sizes or amino acid sizes, and all molecular weight or molecular mass values, given for nucleic acids or polypeptides are approximate, and are provided for description. The abbreviation, “e.g.” is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation “e.g.” is synonymous with the term “for example.”

The term “statistically significant” or “significantly” refers to statistical significance and generally means a two-standard deviation (2SD) above or below a normal or reference level. The term refers to statistical evidence that there is a difference. The decision is often made using the p-value. If within two standard deviations than there is not a statistically significant difference.

It should be understood that this invention is not limited to the particular methodology, protocols, and reagents, and etc., described herein in the examples. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention, which is defined solely by the claims

All references, publications and patents described herein, in the Examples and throughout the Specification, are incorporated herein by reference in their entirety. These publications are provided solely for their disclosure prior to the filing date of the present application. Nothing in this regard should be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention or for any other reason. All statements as to the date or representation as to the contents of these documents is based on the information available to the applicants and does not constitute any admission as to the correctness of the dates or contents of these documents.

Some embodiments of the technology described herein can be defined according to any of the following numbered paragraphs:

-   1. A replication-defective Herpes simplex virus 2 (HSV-2)     recombinant virus, comprising within its genome:     -   a) a first coding sequence, wherein said first coding sequence         encodes HSV-2 glycoprotein B (gB2), wherein said first coding         sequence is operably linked to a first immediate-early promoter;     -   b) a second coding sequence, wherein said second coding sequence         encodes HSV-2 glycoprotein D (gD2), and is operably linked to a         second immediate-early promoter;     -   c) a third coding sequence, wherein said third coding sequence         encodes HSV-2 glycoprotein D (gD2); and is operably linked to a         third immediate-early promoter;     -   and wherein said genome does not comprise a sequence encoding a         functional ICP0 protein, and does not comprise a sequence         encoding functional HSV-2 gG2 protein. -   2. A replication-defective Herpes simplex virus 2 (HSV-2)     recombinant virus, comprising within its genome:     -   a) a first coding sequence, wherein said first coding sequence         encodes HSV-2 glycoprotein B (gB2), wherein said first coding         sequence is operably linked to a first immediate-early promoter,         and said first promoter is an HSV-1 or HSV-2 immediate early         promoter that is operably linked to a first tetracycline         operator (tet-O) sequence;     -   b) a second coding sequence, wherein said second coding sequence         encodes HSV-2 glycoprotein D (gD2) and is operably linked to a         second immediate-early promoter, wherein said second promoter is         operably linked to a second tet-O sequence;     -   c) a third coding sequence, wherein said third coding sequence         encodes HSV-2 glycoprotein D (gD2) and is operably linked to a         third immediate-early promoter, wherein said third promoter is         operably linked to a third tet-O sequence;     -   and wherein said genome does not comprise a sequence encoding a         functional ICP0 protein, and does not comprise a sequence         encoding functional HSV-2 gG2 protein. -   3. The recombinant virus of paragraph 1, wherein said second     promoter and third promoter are a HSV-1 or HSV-2 immediate early     promoter operably linked to a tetracycline operator (tet-O)     sequence. -   4. The recombinant virus of any of paragraphs 1-3, wherein the first     coding sequence is located at the gG2 locus of the HSV-2 genome. -   5. The recombinant virus of any one of paragraphs 1-4, wherein said     genome further does not comprise a sequence encoding a functional     UL19 (VP5) protein. -   6. The recombinant virus of any one of paragraphs 1-4, further     comprising a fourth coding sequence, wherein said fourth coding     sequence encodes a dominant negative mutant HSV-1 or HSV-2 UL9     protein, and is operably linked to a fourth promoter, wherein said     fourth promoter is operably linked to a fourth tet-O sequence. -   The recombinant virus of paragraph 6, further comprising a fifth     coding sequence, wherein said fifth coding sequence encodes a     dominant negative mutant HSV-1 or HSV-2 UL9 protein, and is operably     linked to a fifth promoter, wherein said fifth promoter is operably     linked to a fifth tet-O sequence. -   8. The recombinant virus of any one of paragraphs 6-7, wherein said     fourth sequence encodes UL9-C535C. -   9. The recombinant virus of any one of paragraphs 7-8, comprising     said fifth sequence, wherein said fifth sequence encodes UL9-C535C. -   10. The recombinant virus of any one of paragraphs 1-9, wherein each     of said first, second and third promoters are HSV-1 or HSV-2     immediate early promoters. -   11. The recombinant virus of any one of paragraphs 1-10, wherein     each of said first, second and third promoters are selected from the     group consisting of an ICP0 promoter, an ICP27 promoter, and an ICP4     promoter. -   12. The recombinant virus of any one of paragraphs 1-11, wherein the     first promoter is a HSV-1 or HSV-2 ICP0 promoter. -   13. The recombinant virus of any one of paragraphs 1-12, wherein the     first promoter is a modified HSV-1 or HSV-2 ICP0 promoter comprising     a human cytomegalovirus (hCMV) TATA element. -   14. The recombinant virus of paragraph 13, wherein the first     promoter comprises SEQ ID NO: 08. -   15. The recombinant virus of any one of paragraphs 1-14, wherein     said the fourth and fifth promoters are hCMV immediate-early     promoters. -   16. The recombinant virus of any one of paragraphs 1-15, wherein     said first sequence is a codon optimized sequence. -   17. A replication-defective Herpes simplex virus 2 (HSV-2)     recombinant virus, comprising within its genome:     -   a) a first coding sequence, wherein said first coding sequence         encodes HSV-2 glycoprotein B (gB2), wherein said first coding         sequence is operably linked to a first immediate-early promoter,         and said first promoter is an HSV-1 or HSV-2 immediate early         promoter that is operably linked to a first tetracycline         operator (tet-O) sequence;     -   b) a second coding sequence, wherein said second coding sequence         encodes HSV-2 glycoprotein D (gD2) and is operably linked to a         second HSV-1 or HSV-2 immediate-early promoter, wherein said         second promoter is operably linked to a second tet-O sequence;     -   c) a third coding sequence, wherein said third coding sequence         encodes HSV-2 glycoprotein D (gD2) and is operably linked to a         third HSV-1 or HSV-2 immediate-early promoter, wherein said         third promoter is operably linked to a third tet-O sequence;     -   and wherein said genome does not comprise a sequence encoding a         functional ICP0 protein, and does not comprise a sequence         encoding functional HSV-2 gG2 protein. -   18. A replication-defective HSV-2 recombinant virus, comprising     within its genome:     -   a) a first coding sequence, comprising a codon optimized HSV-2         gB2 sequence operably linked to a first promoter, wherein said         first promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that         is operably linked to a first tet-O sequence;     -   b) a second coding sequence, comprising a codon-optimized HSV         gD2 sequence operably linked to a second promoter, wherein said         second promoter is an HSV-1 ICP4 promoter that is operably         linked to a second tet-O sequence and wherein the second coding         sequence operably linked to the second promoter is located at         the UL26/UL27 intergenic region;     -   c) a third coding sequence, comprising a codon optimized HSV gD2         sequence operably linked to a third promoter, wherein said third         promoter is an HSV-1 ICP27 promoter that is operably linked to a         third tet-O sequence, wherein the third coding sequence operably         linked to the third promoter displaces the UL19 gene;     -   and wherein said genome does not comprise a sequence encoding a         functional ICP0 protein, and does not comprise a sequence         encoding functional HSV-2 gG2 protein. -   19. A replication-defective HSV-2 recombinant virus, comprising     within its genome:     -   a) a first coding sequence, comprising a codon optimized HSV-2         gB2 sequence operably linked to a first promoter, wherein said         first promoter is an HSV-1 or HSV-2 ICP0 or ICP4 promoter that         is operably linked to a first tet-O sequence;     -   b) a second coding sequence, comprising an HSV-2 gD2 sequence         operably linked to a second promoter, wherein said second         promoter is an HSV-1 or HSV-2 ICP0, ICP4, or ICP27 promoter that         is operably linked to a second tet-O sequence;     -   c) a third coding sequence, comprising an HSV-2 gD2 sequence         operably linked to a third promoter, wherein said third promoter         is an HSV-1 or HSV-2 ICP0, ICP4, or ICP27 promoter that is         operably linked to a third tet-O sequence;     -   and wherein said genome does not comprise a sequence encoding a         functional ICP0 protein, and does not comprise a sequence         encoding HSV-2 gG2 protein. -   20. The replication-defective HSV-2 recombinant virus of any one of     paragraphs 17-19, wherein the first coding sequence is located at     the gG2 locus of the HSV-2 genome. -   21. The replication-defective HSV-2 recombinant virus of any one of     paragraphs 17-20, wherein said genome does not comprise a sequence     encoding a functional UL19 (VP5) protein. -   22. The replication-defective HSV-2 recombinant virus of any one of     paragraphs 17-20, further comprising i) a fourth coding sequence,     encoding a dominant negative UL9-C535C protein, and operably linked     to a third promoter, wherein said third promoter is an hCMV     immediate early promoter that is operably linked to a third tet-O     sequence; and ii) a fifth sequence, encoding a dominant negative     UL9-C535C protein, operably linked to a fifth promoter, wherein said     fifth promoter is an hCMV immediate early promoter that is operably     linked to a fifth tet-O sequence. -   23. The recombinant virus of any one of paragraphs 17-22, wherein     the first promoter is an HSV-1 or HSV-2 ICP0 promoter. -   24. The recombinant virus of any one of paragraphs 17-23, wherein     the first promoter is a modified HSV-1 or HSV-2 ICP0 promoter     comprising a human cytomegalovirus (hCMV) TATA element. -   25. The recombinant virus of paragraph 24, wherein the first     promoter comprises SEQ ID NO: 08. -   26. The recombinant virus of any one of paragraphs 17-25, wherein at     least one of the second and third promoters is a HSV-1 or HSV-2     ICP27 promoter operably linked to a tet-O sequence. -   27. The recombinant virus of any one of paragraphs 17-26, wherein at     least one of the second and third promoters is a HSV-1 or HSV-2 ICP4     promoter operably linked to a tet-O sequence. -   28. The recombinant virus of any one of paragraphs 17-28, wherein     each of the second and third promoters are the same, and wherein     said same promoter is an HSV-1 or HSV-2 promoter selected from the     group consisting of: an ICP4 promoter, an ICP27 promoter. -   29. The recombinant virus of any one of paragraphs 17-27, wherein     each of the second and third promoters are different, and wherein     one of these promoters is an HSV-1 or HSV-2 ICP4 promoter, and     wherein the other of these promoters is an HSV-1 or HSV-2 ICP27     promoter. -   30. A replication defective HSV recombinant virus, comprising a     modified HSV-1 or HSV-2 ICP0 promoter comprising a human     cytomegalovirus (hCMV) TATA element, wherein said modified promoter     is operably linked to a transgene. -   31. The replication defective virus of paragraph 30, wherein the     transgene encodes HSV-2 glycoprotein B (gB). -   32. The replication defective virus of paragraph 30 or 31, wherein     said modified promoter comprises SEQ ID NO: 08. -   33. A vaccine comprising the recombinant virus of any one of     paragraphs 1-32 in unit dose form. -   34. A method of immunizing a subject against HSV-1 or HSV-2     infection, comprising administering to said subject the vaccine of     paragraph 33. -   35. The method of paragraph 34, wherein said subject is seropositive     for HSV-1. -   36. The method of paragraph 34, wherein said subject is seropositive     for HSV-2. -   37. The method of paragraph 34, wherein said subject is seronegative     for HSV-1 and HSV-2. -   38. A method for producing the virus of any one of paragraphs 1-32,     the method comprising;     -   a) infecting complementing cells with the virus, wherein the         complementing cells express a functional gene product or         products that are needed for replication of the virus and for         which sequences encoding such are lacking from the virus genome;     -   b) culturing the complementing cells such that the virus         replicates; and     -   c) harvesting said replicated virus from the complementing         cells. -   39. The method of paragraph 38, wherein the complementary cells     further express TetR. -   40. The method of paragraph 38 or 39, wherein the complementary     cells express ICP0 functional gene product. -   41. The method of any one of paragraphs 37-40, wherein the     complementary cells express UL19 (VP5) functional gene product. -   42. A composition comprising a vaccine comprising the recombinant     virus of any of paragraphs 1-32 for use in unit dose form in the     treatment of an infection with HSV-1 or HSV-2. -   43. A composition comprising the virus of any one of paragraphs 1-32     for use in the treatment of an infection with HSV-1 or HSV-2, the     composition comprising;     -   a) infecting complementing cells with the virus, wherein the         complementing cells express a functional gene product or         products that are needed for replication of the virus and for         which sequences encoding such are lacking from the virus genome;     -   b) culturing the complementing cells such that the virus         replicates; and     -   c) harvesting said replicated virus from the complementing         cells.

EXAMPLES Example 1

Construction and Characterization of CJ2-gD2/gB2(UL9) and CJ2-gD2/gB2, and Testing the Vaccine Efficacy of CJ2-gD2/gB2.

The current example describes 1) the construction and in vitro characterization of a CJ2-gD2-derived recombinant virus, CJ2-gD2/gB2(UL9), in which the gB2 gene is inserted at a site encoding a gene needed for viral replication (the UL9 gene) and is operably linked to a tetO-bearing hCMV immediate-early promoter (see FIG. 2), and 2) the construction and in vitro characterization of a CJ2-gD2-derived recombinant virus, CJ2-gD2/gB2, in which the codon-optimized gB2 gene is inserted at a site encoding HSV-2 glycoprotein G (gG2) and is operably linked to a tetO-bearing HSV-1 ICP0 promoter (see FIG. 3).

Materials and Methods

Cells: African Green Monkey Kidney (Vero) cells and the human osteosarcoma line U2OS cells were grown and maintained in Dulbecco's Modified Eagle's Medium (DMEM; Sigma Aldrich) supplemented with 10% fetal bovine serum (FBS) in the presence of 100 U/ml penicillin G and 100 μg/ml streptomycin sulfate (GIBCO, Carlsbad, Calif.) (Yao, et al., J. Virol. 69:6249-58 (1995)). U2OS cells are able to complement functionally for the HSV-1 ICP0 deletion (Yao, et al., J. Virol. 69:6249-58 (1995)). U2CEP4R11 cells are tetR-expressing U2OS cells that were maintained in DMEM plus 10% FBS and hygromycin B at 50 μg/ml (Yao, et al., Hum. Gene Ther. 9:1939-50 (1998)). RUL9 cells are HSV-1 UL9-expressing U2CEP4R-11 cells that were maintained in DMEM plus 10% FBS supplemented with hygromycin and G418 (Yao, et al., Mol. Ther. 13:1133-41 (2006)).

Plasmids: Plasmid p2UL9-V is a pUC19 based plasmid that encodes the PCR amplified HSV-2 UL9 sequences covering 31 bp upstream of the HSV-2 UL9 open reading frame (ORF) to 216 bp downstream of the stop codon of UL9 ORF. p2UL9-lacZ is a p2UL9-V derived plasmid encoding the lacZ gene under the control of the HSV-1 ICP6 promoter. Plasmid p2UL9-TO was created by replacing the PstI-MluI fragment of p2UL9-V, which encodes UL9 amino acids 285-742, with the MluI-PvuII DNA fragment of pCDNA4-TO, which consists of the tetO-hCMV-MCS-poly A transcription unit of pCDNA4-TO. p2UL9TO-gB2 expresses the HSV-2 gB under control of the tetO-containing hCMV major immediate-early promoter (hCMVTO), which was constructed by inserting the HindIII-BamHI-HSV-2 gB ORF-encoding fragment of pMM245 (the kind gift of Martin I. Muggeridge, Louisiana State University Health Sciences Center) into p2UL9-TO at the EcoRV and HindIII sites.

Plasmid pgG2-TO is an HSV-2 gG2 locus-specific shuttle plasmid, that contains a synthesized ˜2.7 kb DNA fragment (GeneArt, Invitrogen) consisting of a) an HSV-2 DNA sequence covering 900 bp to 2 bp upstream of the gG2 ORF; b) an HSV-1 ICP27 poly A signal sequence, which ensures that expression of HSV-2 US3 gene is properly terminated; c) a modified tetO-bearing HSV-1 ICP0 promoter; d) a multiple cloning region; and e) HSV-2 DNA sequences spanning 1 bp downstream of the stop codon of the gG2 ORF to 900 bp downstream of the gG2 stop codon. pgG2-TO/gB2 is a pgG2-TO vector-derived plasmid encoding a codon optimized gB2 under the control of the modified tetO-containing HSV-1 ICP0 promoter. Plasmid pgG2-vector was constructed with the deletion of the tetO sequence in pgG2-TO. The lacZ gene was then inserted into the pgG2-vector at the Hind III and Eco RI sites within the multiple cloning region of the pgG2-vector, resulting in plasmid pgG2-lacZ.

Viruses: Wild-type HSV-2 strain G, strain 186, and strain MS, and HSV-1 strain mP were propagated and plaque assayed in Vero cells (Brans, et al., J. Invest. Dermatol. 129:2470-79 (2009); Zhang, et al., PLOS ONE, 9:e101373 (2014)). CJ2-gD2 is an HSV-2 ICP0-deletion mutant-based non-replicating dominant-negative HSV-2 recombinant virus in which both copies of the HSV-2 ICP0 gene were replaced by DNA sequences encoding the gD2 gene driven by the tetO-bearing HSV-1 major immediate-early ICP4 promoter, while the gene encoding UL9-C535C is under the control of the tetO-containing hCMV major immediate-early promoter in an opposite orientation of the inserted gD2 gene (Akhrameyeva, J. Virol. 85:5036-47 (2011); U.S. Pat. No. 8,809,047). CJ2-gD2 was propagated and plaque assayed in U2CEP4R11 cells or in Vero cells that express tetR and ICP0, e.g. V0R-124 cells (See e.g. U.S. Application Ser. No. 62/515,260, Filed on Jun. 5, 2017 entitled Vero cell lines Stably Expressing HSV ICP0 protein).

CJ2-gD2/lacZ(UL9) is a CJ2-gD2-derived recombinant virus that encodes the lacZ gene under control of the HSV-1 ICP6 promoter at the HSV-2 UL9 locus, which was generated by transfecting U2CEP4R-11 cells with NheI-linearized p2UL9-lacZ and pcDNA-UL9 (Yao, et al., Mol. Ther. 13:1133-41 (2006)) followed by superinfection with CJ2-gD2 as previously described (Lu, et al., J. Invest. Dermatol. 129:1174-84 (2009)). The replacement of the UL9 gene with the lacZ gene at the UL9 locus was confirmed by PCR analysis of CJ2-gD2/lacZ(UL9) viral DNA with the primers that flank the UL9 gene and primers specific for the lacZ gene (Lu, et al., J. Invest. Dermatol. 129:1174-84 (2009)). CJ2-gD2/lacZ was propagated and titered in RUL9 cells.

CJ2-gD2/gB2(UL9) is a derivative of CJ2-gD2/lacZ(UL9), in which the lacZ gene in CJ2-gD2/lacZ(UL9) is replaced with DNA sequences encoding gB2 under control of hCMVTO in plasmid p2UL9TO-gB2. In brief, U2CEP4R11 cells were co-transfected with Nhe-linearized p2UL9TO-gB2 and pcDNA-UL9 followed by superinfection with CJ2-gD2/lacZ(UL9) at an MOI of 5 PFU/cell. Progeny of the superinfection were screened for the recombinational replacement of the lacZ gene of CJ2-gD2/lacZ(UL9) with the DNA sequence containing CMVTO/gB2 by standard plaque assays. Plaques were stained with 5-bromo-4-chloro-3-indolyl-b-D-galactopyranoside (X-Gal) at 72 hr post-infection. White plaques, reflecting the replacement of the lacZ gene by the gB2 DNA-encoding sequence, were isolated. One of the isolates, designated CJ2-gD2/gB2(UL9), yielded uniformly white plaques after four rounds of plaque purification in RUL9 cells.

CJ2-gD2/lacZ is a CJ2-gD2-derived recombinant virus that encodes the lacZ gene under control of the HSV-1 ICP0 promoter at the HSV-2 gG2 locus, which was generated by transfecting U2CEP4R-11 cells with PstI-linearized pgG2-lacZ (Yao, et al., Mol. Ther. 13:1133-41 (2006)) followed by superinfection with CJ2-gD2 as previously described (Lu, et al., J. Invest. Dermatol. 129:1174-84 (2009)). CJ2-gD2/lacZ was propagated and titered in U2CEP4R-11 cells. CJ2-gD2/lacZ was a fourth round plaque-purified CJ2-gD2-derived recombinant virus that exhibits uniform blue plaques in U2CEP4R-11 cells. The plaque-forming efficiency of CJ2-gD2/lacZ in U2CEP4R-11 cells in the absence of tetracycline is 6550-fold higher than in the presence of tetracycline, indicating that like CJ2-gD2, CJ2-gD2/lacZ is capable of expressing high-level of UL9-C535C in the absence of tetracycline repressor, tetR. Additionally, like CJ2-gD2, CJ2-gD2/lacZ replicates efficiently in U2CEP4R-11 cells in the absence of tetracycline.

CJ2-gD2/gB2 is a CJ2-gD2/lacZ-derived recombinant virus, which was generated by super-infection of AscI-linearized pgG2-TO/gB2-transfected U2CEP4R11 cells with CJ2-gD2/lacZ. Progeny of the superinfection were screened for the recombinational replacement of the lacZ gene of CJ2-gD2/lacZ with the gB2-containing DNA sequence by standard plaque assays. Plaques were stained with 5-bromo-4-chloro-3-indolyl-b-D-galactopyranoside (X-Gal) at 72 hours post-infection. White plaques, reflecting the replacement of the lacZ gene by the gB2 DNA-encoding sequence, were isolated. CJ2-gD2/gB2 is a CJ2-gD2/lacZ-derived recombinant that was obtained after four rounds of plaque purification in U2CEP4R-11 cells that express higher levels of gB2 in infected Vero cells compared with cells infected with CJ2-gD2, and CJ2-gD2/lacZ. The genomic location of gB2 in CJ2-gD2/gB2 at the gG2 locus was verified by PCR analysis with gG2-specific primers that flank the insert and primers specific for gB2.

Animal Experiments in Mice

Mice: Female BALB/c mice 6-7 weeks of age were purchased from Charles River Laboratories (Wilmington, Mass.). Mice were housed in metal cages at four mice per cage and maintained on a 12 h-light/dark cycle. Mice were allowed to acclimatize to the housing conditions for 1 week prior to experimentation. All animal experiments were conducted according to the protocols approved by Harvard Medical Area Standing Committee on Animals and the American Veterinary Medical Association. The Harvard Medical School animal management program is accredited by the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC) and meets National Institutes of Health standards as set forth in “The Guide for the Care and Use of Laboratory Animals” (National Academy Press, 1996).

Immunization and challenges: Female BALB/c mice 7- to 8-week-old were randomly divided into several groups and the hair on their left rear upper leg area was trimmed. Mice were either sham-immunized with DMEM (n=6) or immunized with CJ2-gD2/gB2 (n=8), or CJ2-gD2 (n=7) at a dose of 2×10⁶ PFU/mouse or with CJ2-gD2/gB2 (n =8), or CJ2-gD2 (n=8) at a dose of 5×10⁵ PFU/mouse in a volume of 50 μl intramuscular injection into the left rear calf muscle (gastrocnemius) using a 1-ml syringe fitted with a 25G5/8-gauge needle. Individual groups of mice were boosted with the same virus and at the same dose 2 weeks later. Mice were challenged with wild-type HSV-2 strain G three weeks after secondary immunization. Five days prior to challenge, mice were injected subcutaneously in the neck ruff with medroxyprogesterone (SICOR Pharmaceuticals, Inc., Irvine, Calif.) at 3 mg per mouse in a volume of 20 μl (Akhrameyeva, J. Virol. 85:5036-47 (2011)). For intravaginal challenge, mice in all groups were anesthetized, pre-swabbed with a calcium alginate swab (Sterile urethro-genital calcium alginate tipped applicator, Puritan Medical Products company LLC, Guilford, Me. USA) and inoculated intravaginally with 20 μl of culture medium containing 5×10⁵ PFU (50 LD₅₀) of HSV-2 strain G (Morrison, et al., Virology 243:178-87 (1998)). Animals were kept on their backs with their rear part elevated under the influence of anesthesia for 30-45 min post-infection. The CJ2-gD2 and CJ2-gD2/gB2 stocks used in the described animal experiments were prepared and titered on Vero cells that express tetR and ICP0.

Acute infection assays and clinical observations: On days 1, 2, 3, 5, and 7 post-challenge, vaginal mucosae were swabbed with calcium alginate (Brans, et al., J. Invest. Dermatol. 129:2470-9 (2009)). Infectious viruses in swab materials were assessed by standard plaque assay on Vero cell monolayers.

Following challenge with wild-type HSV-2, mice were assessed daily during a 21-day follow-up period for signs of genital lesions and systemic illness. The severity of disease was scored as follows: 0=no sign of herpetic infection, 1=slight genital erythema and edema, 2=moderate genital inflammation, 3=purulent genital lesions and/or systemic illness, 4=hind-limb paralysis, and 5=death (Brans, et al., J. Invest. Dermatol. 129:2470-9 (2009)).

Detection of HSV-2-specific neutralizing antibodies: Blood was collected from tail veins of immunized and mock-immunized mice 4 weeks after primary immunization. Neutralizing serum antibody titers were determined as previously described in the presence of complement (Bourne, et al., Vaccine 14:1230-4 (1996); Brans, et al., J. Invest. Dermatol. 129:2470-9 (2009)) with 250 PFU of wild-type HSV-2 strain 186. The neutralizing titer was expressed as the final serum dilution required to achieve a 50% reduction in HSV PFU relative to the HSV PFU obtained in medium plus complement alone.

Animal Experiment in Guinea Pigs

Preparation of gD2-alum/MPL. Purified recombinant gD2 protein was produced (at U-Protein-Express B.V., Utrecht, the Netherlands) from CHO cells expressing a His-tagged truncated form of gD2 polypeptide consisting of amino acids 1-306 of the mature gD2. The gD2 coding sequence is derived from HSV-2 strain G. The gD2-alum/MPL subunit vaccine was freshly prepared prior to each immunization in a formulation similar to that described by Bourne et al. (Bourne, et al., J. Infect. Dis. 192:2117-23 (2005)). In brief, 50 of the recombinant gD2 protein was first mixed with 1250 μg of alum (Imject Alum, Thermo Scientific, Rockford, Ill.) in a volume of 850 μl on a rotating platform. After 30 minutes of incubation at room temperature, 125 μg of Monophosphoryl Lipid A (MPL) (Avanti Polar Lipids, Inc., Alabaster, Ala.) was added to gD2-alum solution followed by gentle mixing. MPL stock solution was prepared at a concentration of 500 μg/ml containing 10% DMSO (Sigma Aldrich) and stored at −20° C. (InvivoGen, San Diego, Calif.).

Immunization and challenge. Female Hartley guinea pigs (300-350 g) were obtained from Charles River Laboratories (Wilmington, Mass.). Animals were randomly assigned to three groups of six animals each. Each of the groups was either sham-immunized with DMEM, immunized with gD2-alum/MPL at a dose of 5 μg of gD2/animal, or immunized with CJ2-gD2/gB2 at a dose of 5×10⁶ PFU/animal. Each vaccine was administered by intramuscular injection into the quadriceps of the left and right hind limbs in a volume of 50 μl per injection (Bourne, et al., J. Infect. Dis. 192:2117-23 (2005); Zhang, et al., PLOS ONE, 9:e101373 (2014)). Guinea pigs were boosted with gD2-alum/MPL or CJ2-gD2/gB2 on days 14 and 28 post primary immunization. Anesthetized sham-immunized and immunized animals were pre-swabbed with a moist sterile calcium alginate swab (Calgiswab type 2, Puritan Medical Products Company LLC, Maine USA) and challenged intravaginally with 5×10⁵ PFU of HSV-2 strain MS at 3 weeks after the third immunization (Zhang, et al., PLOS ONE, 9:e101373 (2014)).

Clinical observations. After challenge with wild-type HSV-2, the animals were examined daily until day 60 post-challenge. The number of lesions for individual animals was counted and the disease was scored non-blindly as previously described (Zhang, et al., PLOS ONE, 9:e101373 (2014)). The severity of disease were scored as follows: 0=no disease; 1=redness or swelling; 2=a few small vesicles; 3=several large vesicles; 4=several large ulcers with maceration; 5=paralysis; and 6=death.

Analysis of acute and recurrent vaginal shedding of challenge virus. Animals were anesthetized and vaginal mucosae were swabbed on days 1, 2, 3, 5, 7, and 9 post-challenge. Materials on individual swabs were suspended in 1 ml of DMEM containing 10% FBS in the presence of 100 U/ml penicillin G and 100 μg/ml of streptomycin sulfate (Gibco, Carlsbad, Calif.). Infectious virus on swab materials was assessed by standard plaque assay in 60-mm dishes of Vero cells. The minimum titer of challenge virus that could be detected was 1 PFU per original vaginal swab materials.

Statistical analysis: For statistical analysis, un-paired Student's t-tests were performed. Results are considered as statistically significant when the P value is less than 0.05.

Results

In Vitro Characterization of CJ2-gD2/gB2

CJ2-gD2/gB2 expresses gB2 efficiently and is incapable of expressing gG2 in infected Vero cells. The CJ2-gD2, CJ2-gD2/lacZ, and CJ2-gD2/gB2 stocks used in experiments described in this section were prepared and titered on U2CEP4R11 cells. To examine expression of gB2, Vero cells were either mock-infected or infected with wild-type HSV-2, CJ2-gD2, CJ2-gD2/lacZ, or CJ2-gD2/gB2 at an MOI of 5 PFU/cell. Infected cell extracts were prepared at 16 h post-infection. Proteins in infected cell extracts were resolved on SDS-PAGE, followed by immunoblotting with monoclonal antibody against HSV-1/2 gD, or monoclonal antibodies specific for ICP27, gB, and gG2. The results in FIG. 4 showed that while similar levels of ICP27 and gD2 were expressed in cells infected with the indicated viruses, CJ2-gD2/gB2 expressed higher levels of gB2 than CJ2-gD2 and CJ2-gD2/lacZ. As expected, the results showed that CJ2-gD2/gB2 and CJ2-gD2/lacZ are incapable of expressing gG2. This allows convenient discrimination between wild-type HSV infection and presence of CJ2-gD2/gB2 in vaccinated individuals.

To determine the level of expression of gB2 from CJ2-gD2/gB2 and CJ2-gD2/gB2(UL9), we carried out an additional experiment, in which 60 mm dishes of Vero cells in duplicate were either mock-infected or infected with CJ2-gD2, CJ2-gD2/lacZ, CJ2-gD2/gB2, or CJ2-gD2/gB2(UL9) at an MOI of 5 PFU/cell. Infected cell extracts were prepared at 16 h post-infection followed by western blot analyses with monoclonal antibodies against gD2, ICP27 and gB2, respectively. Surprisingly, the results in FIG. 5 showed that levels of gB2 detected in CJ2-gD2/gB2-infected cells were markedly higher than in cells infected by CJ2-gD2/gB2(UL9). The levels of gB2 detected in CJ2-gD2/gB2-infected cells were also markedly higher than in cells infected by CJ2-gD2, as well as CJ2-gD2/lacZ. Comparable levels of ICP27 and gD2 were detected among cells infected with these four indicated viruses. Taken together, the data indicates that CJ2-gD2/gB2, where gB2 is located at the gG2 locus expresses gB2 more efficiently than CJ2-gD2 and CJ2-gD2/gB2(UL9), where the gB2 is located at the UL9 locus.

Inhibition of wild-type HSV-2 replication by CJ2-gD2/gB2. To examine the effectiveness of CJ2-gD2/gB2 in blocking wild-type HSV-2 infection in co-infected cells, Vero cells in triplicate were infected with either wild-type HSV-2 at an MOI of 2 PFU/cell, wild-type HSV-2 at an MOI of 2 PFU/cell and CJ2-gD2 at an MOI of 5 PFU/cell, wild-type HSV-2 at an MOI of 2 PFU/cell and CJ2-gD2/gB2 at an MOI of 5 PFU/cell, or wild-type HSV-2 at an MOI of 2 PFU/cell and the HSV-2 ICP0 deletion mutant, N2-lacZ at an MOI of 5 PFU/cell. Infected cells were harvested at 18 h post-infection and viral titers were determined on Vero cell monolayers. The data presented in FIG. 6 show that CJ2-gD2/gB2 is as effective as CJ2-gD2 in blocking wild-type HSV-2 infection in co-infected cells. Specifically, yields of wild-type HSV-2 in cells co-infected with CJ2-gD2/gB2 was more than 750-fold lower than in cells singly infected by wild-type HSV-2. Little reduction in wild-type virus yield was detected when a similar co-infection experiment was performed with N2-lacZ.

Investigating the Vaccine Efficacy of CJ2-gD2/gB2 Against HSV-2 Genital Infection in Mice

CJ2-gD2/gB2 is as effective as CJ2-gD2 in eliciting HSV-2-specific neutralizing antibodies in immunized mice. The ability of CJ2-gD2/gB2 to elicit anti-HSV-2-specific neutralizing antibodies was determined in mice immunized with CJ2-gD2/gB2 or CJ2-gD2 at a dose of 2×10⁶ PFU or 5×10⁵ PFU. As shown in FIG. 7, the HSV-2-specific neutralization antibody titer in mice immunized with CJ2-gD2/gB2 were on average of 300 at a low dose (5×10⁵ PFU) and 600 at the high dose (2×10⁶ PFU), while the HSV-2-specific neutralization antibody titer in mice immunized with CJ2-gD2 was on average of 629 at a high dose, and 325 at a low dose.

CJ2-gD2/gB2 is as effective as CJ2-gD2 in induction of protective immunity against HSV-2 genital infection and disease in mice. The results in FIG. 8 show that immunization with CJ2-gD2/gB2 or CJ2-gD2 at both high and low doses completely protects mice from development of local genital lesions (FIG. 8B) and these mice exhibit no signs of systemic disease after challenge with wild-type HSV-2, whereas 100% of mock-vaccinated mice developed severe genital lesions and succumbed to wild-type HSV-2 infection by day 9 post-challenge (FIG. 8C). The yields of challenge virus were 418-, 155-, and 495-fold lower in mice immunized with a high dose of CJ2-gD2/gB2 compared with those in mock-immunized mice on day 1 (P<0.001), day 2 (P<0.001), and day 5 (p=0.002) post challenge, respectively (FIG. 8A). The HSV-2 viral shedding was reduced 542-, 134-fold, and 634-fold in mice immunized with CJ2-gD2 at the same dose on day 1 (p=0.002), day 2 (p<0.001), and day 5 (p<0.001) post challenge than mock-immunized mice, respectively.

Immunization with CJ2-gD2/gB2 at a low dose also led to 251-, 77- and 241-fold reduction in the viral titer of challenge virus recovered from vaginal swabs on day 1 (P<0.001), day 2 (P<0.001), and day 5 (p<0.001) compared with those from mock-immunized mice, respectively. Similar results were observed in mice immunized with a low dose of CJ2-gD2.

The experimental results described above show that the vaccine efficacy of CJ2-gD2/gB2 and CJ2-gD2 is essentially the same at the tested immunization doses. Whether CJ2-gD2/gB2 at a lower immunization dose would offer a better protective immunity than CJ2-gD2 remains to be investigated. Similarly, whether the purified CJ2-gD2/gB2 vaccine construct, free of contamination with infected cell proteins, such as gB2, would provide superior vaccine efficacy to similarly purified CJ2-gD2 remains to be determined. In any case, we have determined that the absence of gG2 expression from the novel CJ2-gD2/gB2 vaccine does not remove its capacity to induce protective immunity to HSV2 infections and thus, we have generated a novel efficacious vaccine that also enables serological monitoring in a clinical setting to differentiate between infection with wild type HSV-2 and with the vaccine vector. This is a significant advancement in the field of HSV vaccines.

Immunization with CJ2-gD2/gB2 elicits long-term protective immune response against HSV-2 genital infection. Sixteen 7-8 week old female BALB/c mice were divided into 2 groups of 8 mice each. Mice were either sham-immunized or immunized with CJ2-gD2/gB2 at a dose of 1×10⁶ PFU/mouse as described earlier. Mice were boosted with the same dose of CJ2-gD2/gB2 twice on days 14 and 28 post primary immunization, respectively. Five months after the third immunization, mice were challenged intravaginally with HSV-2 strain G at 5×10⁵ PFU/mouse. Vaginal swabs were taken on days 1, 2, 3, 5, and 7 after challenge. Mice were observed during a 21-day follow-up period for the incidence of genital and disseminated HSV-2 disease.

The results presented in FIG. 9 show that immunization with CJ2-gD2/gB2 can offer an effective protective immune response against HSV-2 vaginal infection at 5 months post last immunization. Yields of challenge HSV-2 were reduced 178-fold on day 1 (p<0.001), 40-fold on day 2 (p<0.001), and 185-fold on day 5 (p<0.001) post-challenge in the immunized animals compared to the sham-immunized mice (FIG. 9A). No HSV-2 was detected in the vaginal swabs collected on day 7 post-challenge in the CJ2-gD2/gB2 vaccinated groups. While all sham-immunized mice died by day 9 post-challenge, none of CJ2-gD2/gB2-immunized animals experienced any signs of HSV-2 genital disease or neurological complications associated with HSV-2 infection (FIG. 9B, FIG. 9C).

Investigating the Vaccine Efficacy of CJ2-gD2/gB2 Against HSV-1 Genital Infection in Mice

CJ2-gD2/gB2 can elicit a strong HSV-1-specific neutralizing antibody response in immunized mice. Results in FIG. 10 show that the HSV-1-specific neutralization antibody titer in mice immunized with CJ2-gD2/gB2 were on average 200 following primary immunization and reached an average of 686 at 2 weeks after boost immunization.

CJ2-gD2/gB2 is highly effective in induction of cross protective immunity against HSV-1 genital infection and disease in mice. The results in FIG. 11 show that immunization with CJ2-gD2/gB2 completely protects mice from development of local genital lesions and systemic disease after challenge with wild-type HSV-1, whereas 100% of mock-vaccinated mice developed genital lesions (FIG. 11B) and 5 of 7 mice died from wild-type HSV-1 challenge infection (FIG. 11C). The yields of challenge virus were about 510-, 610-, and 20500-fold lower in CJ2-gD2/gB2-immunized mice than those mock-immunized mice on day 1 (P<0.0001), day 2 (P<0.0001), and day 3 (p<0.0001) post challenge, respectively (FIG. 11A). None of CJ2-gD2/gB2-immunized mice had detectable virus shedding on day 5 post-infection, while all mock-immunized animals continued to shed virus at an overall average yield of 1,270 PFU/ml.

Investigating the Vaccine Efficacy of CJ2-gD2/gB2 Against HSV-2 Genital Infection in Guinea Pigs

CJ2-gD2/gB2 is significantly more efficient than gD2-subunit vaccine in eliciting HSV-2-specific neutralizing antibody response. Adjuvanted gD2 protein has previously been used by others in advanced clinical trials, as described above. The results presented in FIG. 12 show that the neutralizing antibody titers detected in the CJ2-gD2/gB2-immunized animals are 20- and 14-fold higher than those detected in the gD2-alum/MPL-immunized animals after the second and third immunizations, respectively (p<0.0001). There was a significant increase in the HSV-2 neutralizing antibody titers from the first to the second vaccination with an average titer of 2,167 after the second immunization and 6,500 after the third immunization. The average HSV-2 neutralizing antibody titer in gD2-alum/MPL-immunized animals was 108 after the second immunization and ˜467 after the third immunization. No HSV-2-specific neutralizing antibody was detected in serum from the sham-immunized animals at 1:10-dilution.

CJ2-gD2/gB2 is significantly more effective than gD2-alum/MPL in protecting against acute replication of challenge HSV-2 as well as primary and recurrent HSV-2 genital disease. The sham-immunized and immunized animals described in FIG. 12 were challenged intravaginally with wild-type HSV-2 as detailed in the Materials and Methods. The results in FIG. 13A showed that the yields of challenge virus in sham-immunized controls were ˜4.2×10⁶ PFU/ml, ˜4.1×10⁶ PFU/ml, and ˜1.6×10⁵ PFU/ml on days 1, 2, and 3 post-challenge, respectively. The yields of challenge virus in the CJ2-gD2/gB2-immunized animals were 4,396-(p<0.0001), 80,059-(p<0.0001), and ˜14,700 (p<0.0001)-fold lower than the sham-immunized animals on days 1, 2, and 3 post-challenge, respectively, and 166-(p<0.0001), 493-(P<0.005), and 113 (p<0.0004)-fold lower than in the gD2-alum/MPL-immunized animals on days 1, 2, and 3 post-challenge. By day 5, none of CJ2-gD2/gB2-immunized animals had detectable virus shedding, while all gD2-alum/MPL-immunized animals continued to shed virus. The duration of detectable challenge virus shedding was 2.3 days in the CJ2-gD2/gB2-immunized animals compared with 4.6 days in the gD2-alum/MPL group (p=0.001) and 9 days in the sham-immunized control (p<0.0001) (FIG. 13B).

The impact of immunization with CJ2-gD2/gB2 and gD2-alum/MPL in protecting against primary skin lesions as well as recurrent disease is summarized in FIG. 14. As shown in FIG. 14A, all the sham-immunized animals developed multiple genital herpetic lesions following challenge with wild-type HSV-2 and five of six animals succumbed to HSV-2 infection by day 14 post-challenge. None of CJ2-gD2/gB2 immunized animals exhibited signs of primary genital disease, while all gD2-alum/MPL-immunized animals experienced primary herpetic skin lesions with a total of 30 lesions detected between days 5 and 8 (FIG. 14B). Moreover, one of the gD2-alum/MPL immunized animals died on day 11 post-challenge and an additional animal had to be sacrificed on day 26 post-challenge due to the severity of local and systemic herpetic disease (FIG. 14C). Collectively, the results demonstrate that CJ2-gD2/gB2 is significantly superior to gD2-alum/MPL in protecting against HSV-2 primary genital disease in guinea pigs (FIG. 14B, p<0.0001).

The results in FIG. 15 showed that immunization with CJ2-gD2/gB2 is significantly more effective than immunization with gD2-alum/MPL in protecting against recurrent HSV-2 genital disease in terms of cumulative recurrent lesions per animal (0 vs. 6, p=0.04) and days on which animals exhibited recurrent disease (0 vs. 3.75, p=0.03). In this experiment, none of the CJ2-gD2/gB2-immunized animals (e.g., guinea pigs) experienced detectable recurrent disease compared with 50% observed in the gD2-alum/MPL subunit vaccine group.

Example 2

Evaluation of CJ2-gD2/gB2 as a Therapeutic Vaccine Against HSV-2 Genital Herpes in Guinea Pigs

Experimental Design

Twenty-eight female Hartley guinea pigs were intravaginally infected with 5×10⁵ PFU of HSV-2 strain MS/wp28 on day 0 as previously described (Zhang, et al., PLOS ONE, 9:e101373 (2014)). On day 21 post-intravaginal infection, the surviving animals (27 of 28) were divided into 2 groups based on the disease scores as well as titers of virus shedding on days 2 and 5. Animals in group 1 (n=13) were sham-immunized with DMEM, while animals in group 2 (n=14) were immunized with CJ2-gD2/gB2 at a dose of 5×10⁶ PFU/animal in 50 μl. Animals were boosted with DMEM or CJ2-gD2/gB2 two weeks later. All animals were examined for clinical scores daily until day 70 post-challenge. The number of lesions for individual animals was counted and the disease was scored non-blindly as previously described: 0=no disease; 1=redness or swelling; 2=a few small vesicles; 3=several large vesicles; 4=several large ulcers with maceration; 5=paralysis; and 6=death. Blood sample was collected from the saphenous veins on day 21, day 35 and day 49 post-intravaginal infection. On day 2 and 5 post-intravaginal infection, the vaginal mucosae were swabbed under anesthesia.

Materials and Methods

Intravaginal infection. Twenty-eight female Hartley guinea pigs were anesthetized and pre-swabbed followed by intravaginal infection with 5×10⁵ PFU of HSV-2 strain MS/wp28 (A gift of Nigel Bourne, University of Texas Medical Branch, Tex.).

Analysis of acute vaginal shedding of wild-type HSV-2. Animals were anesthetized and vaginal mucosae were swabbed on days 2 and 5 post-intravaginal infection. Infectious virus on swab materials was assessed by standard plaque assay in 60-mm dishes of Vero cells. The minimum titer of challenge virus that could be detected was 1 PFU per original vaginal swab materials. For analysis of recurrent virus shedding, swabs were taken daily from days 27 to 52 post challenge. DNA was isolated from swab materials with the DNeasy tissue kit (Qiagen, Santa Clarita, Calif.), and stored at −20° C.

Clinical observations. After infection with wild-type HSV-2, the animals were examined daily until day 70 post-challenge. The number of lesions for individual animals was counted and the disease was scored non-blindly as previously described: 0=no disease; 1=redness or swelling; 2=a few small blisters; 3=several large vesicles; 4=several large ulcers with maceration; 5=paralysis; and 6=death.

Immunization. On day 21 post-intravaginal infection, surviving animals (27 of 28) were divided into 2 groups based on the disease scores as well as titers of virus shedding on days 2 and 5 such that animals in both groups experienced similar degrees of primary infection and disease (Table 1). Animals in group 1 (n=13) were sham-immunized with DMEM, while animals in group 2 (n=14) were immunized with CJ2-gD2/gB2 at a dose of 5×10⁶ PFU/animal. Vaccine was administered i.m. into the quadriceps of the left and right hind limbs in a volume of 50 μl per injection. Guinea pigs were boosted with CJ2-gD2/gB2 two weeks later.

Neutralizing antibody assay. Blood was obtained from the saphenous veins on day 21 post-intravaginal infection, prior to immunization and 14 days after primary immunization as well as boost immunization. HSV-2-specific neutralizing antibody titers in serum collected from each animal were determined in the presence of complement as previously described (Zhang, et al., PLOS ONE, 9:e101373 (2014)).

Quantitative real-time PCR. For analysis of recurrent virus shedding, swabs were taken daily from days 27 to 52 post-intravaginal infection. DNA was isolated from swab materials with the DNeasy tissue kit (Qiagen, Santa Clarita, Calif.), and stored at −20° C. (see protocol in Attachment VII). The presence of HSV-2 DNA was quantified by real-time PCR (Applied Biosystems 7300 Real-Time PCR System) with 10 μl of 200-400 ng vaginal swab DNA and primers specific to the HSV DNA polymerase (Forward: 5′ GCT CGA GTG CGA AAA AAC GTT C, Reverse: 5′ CGG GGC GCT CGG CTA AC) as previously described (see protocol in Attachment VIII). The minimal copies of HSV-2 viral DNA that could reliably be detected were 2.5 to 5 copies per reaction.

Statistical analysis. For statistical analysis, un-paired Student's t-tests and un-paired Fisher's exact test were performed. Results are considered to be statistically significant when the P value is less than 0.05.

Results

Intravaginal infection of guinea pigs with wild-type HSV-2 strain MS, wp/28. Of 28 intravaginally infected animals, 19 experienced primary herpetic disease and one animal was euthanized on day 8 post-intravaginal infection due to severity of disease. Nine animals did not experience primary HSV-2 genital disease with vaginal titers ranging from 4.4×10e3 PFU to 2.1×10e4 PFU/ml on day 2 post-challenge. The lowest vaginal titer for animals experiencing primary genital disease was 4.8×10e3 PFU/ml on day 2 post-intravaginal infection. On day 21 post-intravaginal infection, the 27 surviving animals were divided into 2 groups based on the disease scores as well as titers of virus shedding on days 2 and 5 (FIG. 16 and Table 1). Group 1 (n=13) was subsequently sham-immunized with DMEM, while animals in group 2 (n=14) were immunized with CJ2-gD2/gB2 at a dose of 5×106 PFU/animal.

TABLE 1 Intravaginal infection of guinea pigs with wildtype HSV-2 strain MS, wp/28. Virus titer, No. of mean ± SD (log₁₀ PFU/ml) Primary disease guinea pigs^(a) Day 2 Day 5 Incidence^(b) severity^(c) All 27/28 4.32 ± 0.44  2.25 ± 0.84  19/28 6.89  Group 1 13/13 4.32 ± 0.47  2.12 ± 0.75   9/13 5.62  Group 2 14/14 4.33 ± 0.43^(d) 2.34 ± 0.93^(e)  9/14 8.07^(f) ^(a)No. of guinea pigs that were analyzed for virus titers on day 2 and 5/total no. of guinea pigs inoculated. ^(b)No. of guinea pigs with clinical signs/total no. of guinea pigs inoculated. ^(c)Cumulative mean clinical scores from day 1 to day 20 after challenge (before prime immunization at day 21) ^(d)group 1 vs group 2 p = 0.98; ^(e)group 1 vs group 2 p = 0.53; ^(f)group 1 vs group 2 p = 0.33

Induction of HSV-2-specific neutralizing antibody response by CJ2-gD2/gB2 in the immunized animals. Anti-HSV-2 neutralizing antibody titers on day 21 post-intravaginal challenge are about the same in both groups, sham- and CJ2-gD2/gB2 immunized, while the neutralizing antibody titers detected in the CJ2-gD2/gB2 immunized animals are 3.12- and 5.36-fold higher than in sham-immunized animals after the first and second immunization, respectively (FIG. 17). There was a 2.42-fold increase in the HSV-2 neutralizing antibody titers from the first to the second vaccination (p<0.0003) with an average titer of 886 two weeks after the first immunization and 2183 two weeks after the second immunization. These results demonstrate that therapeutic immunization can significantly enhance the HSV-2-specific neutralizing antibody response in the immunized animals.

Immunization with CJ2-gD2/gB2 is effective in protecting against recurrent genital disease in the immunized animals. The impact of immunization with CJ2-gD2/gB2 in protecting against recurrent genital skin lesions was monitored after prime immunization. Among sham-immunized animals, 9 of 13 animals (69%) experienced episodic recurrences during the 50 days follow-up (FIG. 18 and Table 2), while only 2 of 14 immunized animals (14%) had detectable recurrent skin lesions during this period (p=0.0063). The average of cumulative number of recurrent lesions per animal in the sham-immunized animals from days 21 to 70 post-intravaginal infection was 3/animal compared with 0.43/animal seen in the CJ2-gD2/gB2 immunized animals (p<0.0001) (FIG. 19A).

The frequency of recurrent genital disease was 2.62 days/animal in the sham-immunized animals compared with 0.43 days/animal in the CJ2-gD2/gB2 immunized animals (p<0.0001) (FIG. 19B). No recurrent disease was detected in CJ2-gD2/gB2 immunized animals until 9 days after the second immunization. Collectively, the results show that therapeutic immunization with CJ2-gD2/gB2 is effective in protecting against recurrent HSV-2 genital disease, i.e. the number of animals experiencing episodic recurrences, the cumulative number of recurrent lesions and the duration of recurrent disease were reduced significantly.

Immunization with CJ2-gD2/gB2 is effective in reducing recurrent virus shedding. One of fourteen CJ2-gD2/gB2 immunized animals (7%) had detectable virus shedding for a total of 7 days, while seven of thirteen sham-immunized animals (53.8%) experienced detectable virus shedding for a total of 26 days (FIG. 20 and Table 2). These results indicate that therapeutic immunization with CJ2-gD2/gB2 is also effective in protecting against recurrent virus shedding in the immunized animals compared to sham-immunized control in terms of percent of animals experiencing detectable virus shedding (p=0.013) and frequency (p=0.0003) in recurrent virus shedding.

TABLE 2 Overview of effects of CJ2-gD2/gB2 vaccine on recurrent disease and viral shedding in the genital tract. Recurrent disease Viral shedding Immunized Frequency, Quantity, Frequency, Quantity, Group Incidence^(a) mean ± SD^(b) mean^(c) Incidence^(d) mean ± SD^(e) mean^(f) Sham 9/13  2.62 ± 3.82  3    7/13  2.0 ± 3.51  2   CJ2- 2/14^(g) 0.43 ± 5.10^(h) 0.43^(i) 1/14^(k) 0.5 ± 1.87^(m) 0.5 gD2/gB2 ^(a)No. of guinea pigs with recurrent lesions/total no. of infected guinea pigs that could be evaluated. ^(b)Days with recurrent lesions between days 21 and 70 post-intravaginal infection (days/animal). ^(c)Cumulative no. of recurrent lesions between days 21 and 70 post-intravaginal infection (lesions/animal) ^(d)No. of guinea pigs shedding virus into the genital tract/total no. of infected guinea pigs evaluated. ^(e)Days on which viral DNA was detected in vaginal swabs between days 27 and 52 post-intravaginal infection (days/animal). ^(f)No. of viral genomes equivalents detected by qPCR in vaginal swap samples. ^(g)p = 0.0063; ^(h)p < 0.0001; ^(i)p < 0.0001; ^(k)p = 0.013; ^(m)p = 0.0003.

CONCLUSIONS

Therapeutic immunization of guinea pigs, previously infected with wild-type HSV-2, with CJ2-gD2/gB2 significantly elevated levels of HSV-2-specific neutralizing antibody responses. Importantly, therapeutic immunization led to a significant reduction in recurrent HSV-2 genital disease and recurrent virus shedding compared with sham-immunized control. The observed therapeutic vaccine efficacy in this study is considerably higher than previously reported with other HSV-2 vaccine candidates [1, 2, 3, and 4].

REFERENCES

-   1. Hoshino Y, Dalai S K, Wang K, Pesnicak L, Lau T Y, Knipe D M,     Cohen J I, Straus S E. Comparative efficacy and immunogenicity of     replication-defective, recombinant glycoprotein, and DNA vaccines     for herpes simplex virus 2 infections in mice and guinea pigs. J     Virol. 2005 January; 79(1):410-8. Erratum in: J Virol. 2005 April;     79(7):4554. -   2. Awasthi S, Zumbrun E E, Si H, Wang F, Shaw C E, Cai M, Lubinski J     M, Barrett S M, Balliet J W, Flynn J A, Casimiro D R, Bryan J T,     Friedman H M. Live attenuated herpes simplex virus 2 glycoprotein E     deletion mutant as a vaccine candidate defective in neuronal spread.     J Virol. 2012 April; 86(8):4586-98. -   3. Skoberne M, Cardin R, Lee A, Kazimirova A, Zielinski V, Garvie D,     Lundberg A, Larson S, Bravo F J, Bernstein D I, Flechtner J B,     Long D. An adjuvanted herpes simplex virus 2 subunit vaccine elicits     a T cell response in mice and is an effective therapeutic vaccine in     Guinea pigs. J Virol. 2013 April; 87(7):3930-42. -   4. Veselenak R L, Shlapobersky M, Pyles R B, Wei Q, Sullivan S M,     Bourne N. A Vaxfectin(®)-adjuvanted HSV-2 plasmid DNA vaccine is     effective for prophylactic and therapeutic use in the guinea pig     model of genital herpes. Vaccine. 2012 Nov. 19; 30(49):7046-51.

Example 3

Evaluation of Purified CJ2-gD2/gB2 Virus as a Prophylactic Vaccine Against HSV-2 Genital Herpes Infection in Mice

Materials and Methods

Virus purification. Purification of CJ2-gD2 and CJ2-gD2/gB2 viruses can be done using a chromatography-based purification as described in Mundle, S. T., et al. PLOS One. February 2013; 8(2):e57224, which is incorporated herein in its entirety. This purification requires a viral harvest method that utilizes a chemical treatment of infected cells by the sulfated polymeric anion dextran sulfate (DS) to elute the virus from the surface of the cells. The purification procedure led to a >3 log and >5 log reduction of host cell protein and host cell DNA, respectively, in the CJ2-gD2/gB2 virus batch.

Animal experiments in mice. Female Balb/cAnNCrl mice were purchased from Charles River Laboratories (Sulzfeld, Germany) and kept at the AAALAC-certified institutional animal facility under specified pathogen-free conditions. Animals were co-housed per group in IVC cages using compressed sawdust as bedding, under controlled conditions of temperature, humidity and light (12-hour light, 12-hour dark cycles). Mice were allowed to acclimatize to the housing conditions for 12 days prior to experimentation. Experimental procedures were approved by the local animal experiments ethical committee and conducted according to the Dutch Experiments on Animals Act and the Council of Europe.

Immunization and challenges: Female Balb/cAnNCrl mice 7- to 8-week-old were randomly divided into three groups (n=8 each). Mice were either sham-immunized with formulation buffer or immunized with purified CJ2-gD2/gB2 at a dose of 1.8×10⁵, 1.8×10⁶ or 1.8×10⁷ PFU or crude CJ2-gD2/gB2 at 1.43×10⁶ PFU/mouse in a volume of 50 μl by intramuscular injection into both quadriceps muscles of the hind legs. Individual groups of mice were boosted with the same virus and at the same dose 2 weeks later. Mice were challenged with wild-type HSV-2 strain G three weeks after secondary immunization. Five days prior to challenge, mice were injected subcutaneously in the neck ruff with medroxyprogesterone (Depo-Provera, Pfizer) at 3 mg per mouse in a volume of 100 For intravaginal challenge, mice in all groups were anesthetized, pre-swabbed with a calcium alginate swab and inoculated intravaginally with 20 μl of culture medium containing 5×10⁵ PFU of HSV-2 strain G (Morrison, et al., Virology 243:178-87 (1998)). Animals were kept on their backs with their rear part elevated under the influence of anesthesia for 30-45 min post-infection.

Acute infection assays and clinical observations: On days 1, 2, 4, and 7 post-challenge, vaginal mucosae were swabbed with calcium alginate to assess viral shedding. Infectious viruses in swab materials were assessed by standard plaque assay on Vero cell monolayers. HSV-2 plaque assays were performed to measure the virus titer in mouse vaginal swabs. Briefly, Vero cells were seeded in 6-well cell-culture plates one day prior to infection. On the day of infection, culture medium was discarded and 300 μl serially diluted mouse vaginal swabs and controls were added to each well, and incubated for 1.5 hr at 37° C. Subsequently, 3 mL of agarose mix was added to the virus and cells. After the agarose solidified the plates were incubated at 37° C. for 3 days. At day 3, cells were fixed and stained, dried at room temperature before counting of plaques. Following challenge with wild-type HSV-2, mice were assessed daily during a 21-day follow-up period for signs of genital lesions and systemic illness. The severity of disease was scored as follows: 0=no sign of herpetic infection, 1=slight genital erythema and edema, 2=moderate genital inflammation, 3=purulent genital lesions and/or systemic illness, and 4=hind-limb paralysis (Brans, et al., J. Invest. Dermatol. 129:2470-9 (2009)).

Detection of HSV-2-specific neutralizing antibodies: Blood was collected from the saphenous veins of immunized and mock-immunized mice at days 0 (before prime), 13 (before boost), and 34 (before challenge) and stored after heat inactivation for measurements of immunological parameters. Neutralizing serum antibody titers were determined in the ELVIS reporter assay on BHKICP6-lacZ cells. These cells stably express lacZ under the HSV-1 ICP6 promoter. ICP0 acts as a major activator of this promoter after successful HSV infection. Consequently, cells that are infected with HSV-2 express beta-galactosidase (β-gal). β-gal is subsequently detected using a chemiluminescent reporter gene assay. In the presence of complement, a serial dilution of serum was added to the reporter cells prior to addition of virus. The 50% neutralization titer (IC50) was calculated by non-linear regression using a 4-parameter logistic curve fit per sample. This assay was adapted from Blevins et al. PLoS One. 2015; 10(12):e0144738, which is incorporated herein by reference in its entirety.

Exploratory detection of cellular immunity: Mice immunized with either sham-immunized with formulation buffer (n=2) or immunized with purified CJ2-gD2/gB2 at a dose of 1.8×10⁶ PFU/mouse (n=6) as described above were sacrificed 3 weeks after boost. The mice received medroxyprogesterone (MPG) 5 days before sacrifice. Cellular immune responses were determined by stimulating splenocytes with pools of 15 mer peptides (>90% pure, with 11 AA overlap) spanning gB2 and gD2 proteins, i.e. a gD2 pool of 96 peptides covering all gD2, a gB2 pool (#1) of peptides 1-95 of the gB2 extracellular region, a gB2 pool (#2) of peptides 96-192 of the gB2 extracellular region, and a gB2 pool (#3) of peptides 193-224 covering the gB2 transmembrane and intracellular region. In addition, a previously described 13-mer VP11/12 peptide (AFLTGADRSVRLA; (SEQ ID NO: 41)); as described in, e.g., Muller et al. Journal of General Virology. 2009; 90: 1153-1163, which is incorporated herein by reference in its entirety, and a 9-mer ICP27 peptide (HGPSLYRTF; (SEQ ID NO: 42)), as described in, e.g., Haynes et al. Vaccine 2006; 24: 5016-5026, which is incorporated herein by reference in its entirety) were used as stimulants. The induction of IFNγ-producing cells was measured by ELISPOT.

Results

Purified CJ2-gD2/gB2 is as effective as CJ2-gD2/gB2 in crude cell lysate in eliciting HSV-2-specific neutralizing antibodies in immunized mice. The ability of purified CJ2-gD2/gB2 to elicit anti-HSV-2-specific neutralizing antibodies was determined in mice immunized with purified CJ2-gD2/gB2 at a dose of 1.8×10⁵, 1.8×10⁶ or 1.8×10⁷ PFU or crude CJ2-gD2/gB2 at 1.43×10⁶ PFU or formulation buffer. As shown in FIG. 22, all vaccine groups showed a significant increase in HSV-2 neutralizing antibody titers compared to the formulation buffer group (Mann-Whitney). The indicated p values for the purified vaccine were obtained via a stepwise comparison of vaccinated groups (from high to low vaccine dose) with the formulation buffer group. The HSV-2-specific neutralization antibody titer three weeks after boost immunization in mice immunized with a medium and high dose of purified CJ2-gD2/gB2 were comparable to titers induced by crude vaccine.

Purified CJ2-gD2/gB2 is as effective as CJ2-gD2/gB2 in crude cell lysate in induction of protective immunity against HSV-2 genital infection and disease in mice. The results in FIG. 23 show that comparable to immunization with crude CJ2-gD2/gB2, immunization with purified CJ2-gD2/gB2 at high and medium doses completely protects mice from development of local genital lesions and that these mice exhibit no signs of systemic disease after challenge with wild-type HSV-2, whereas 100% of sham-vaccinated mice developed severe genital lesions (FIG. 23A) and succumbed to wild-type HSV-2 infection by day 7 post-challenge (FIG. 23B). As shown in FIG. 24, compared with the sham-immunization group, high and mid dose (1.81×10⁷, 1.81×10⁶ pfu/mouse) purified CJ2-gD2/gB2 as well as crude vaccine immunized groups showed significant decrease in virus shedding titers on day 1, 2 and 4 post challenge (p<0.001, Wilcoxon, stepwise approach, if applicable, starting from the highest dose). The low dose (1.81×10⁵ pfu/mouse) purified CJ2-gD2/gB2 immunized group also showed significant decrease in virus shedding titers on day 1, 2 and 4 post challenge (p<0.01, p<0.001 and p=0.026, respectively). No significant differences in shedding titers were observed on day 7. Mouse vaginal virus shedding in the mock immunized group reduced over time to below the limit of detection on day 7.

Purified CJ2-gD2/gB2 elicits HSV-2-specific cellular immune responses in immunized mice. As shown in FIG. 25, CJ2-gD2/gB2 induces T cell responses (IFNγ+) against gB2, gD2 and other vaccine components. IFNγ release was detected after stimulation with the peptide pool covering the N-terminal extracellular part of gB2, with the complete gD2 peptide pool, and with peptides specific for the viral proteins ICP27 and VP11/12.

Example 4

Vero Cell Lines Stably Expressing ICP0 Protein

We were able to successfully minimize the cytotoxic effect of ICP0 by using a minimal promoter pMF-3. To establish the ICP0-expressing stable cell lines, we constructed an ICP0-expressing plasmid, pMF3-ICP0. Linearized pMF3-ICP0 plasmid was then transfected into CCL-81 Vero cells along with linearized pcDNA3 by Lipofectamine 2000 (Invitrogen Inc.). At 30 hours post-transfection, cells were seeded into 100 mm dishes at various cell density and were grown in DMEM growth medium containing G418 at 400 μg/ml. G418 resistant colony cells were assayed by its ability to complement the growth of HSV-2 ICP0 null mutant, N2-lacZ, benchmarked against U2OS cells. Among more than 1000 G418-resistant colonies that were selected, V0-584 cells represented the only G418-resistant and ICP0-expressing stable cell line that can complement the plaque-formation of N2-lacZ at level comparable to U2OS cells. The plaque-forming efficacy of N2-lacZ in passage 7 V0-584 cells is ˜2-fold lower than that of U2OS cells and ˜120-fold higher than that of normal CCL-81 cells. The complementing efficiency of V0-584 cells for N2-lacZ remained 2-3 fold lower than that of U2OS cells at passage 33. These cells are further described in U.S. Application Ser. No. 62/515,260, filed on Jun. 5, 2017.

We also generated a tetR- and ICP0-expressing Vero cell line that can complement the plaque forming efficiency. To establish tetR- and ICP0-expressing stable CCL-81 Vero cells, V0-584 cells were transfected with linearized pMF-tetR along with linearized pCDNA4/TO (Invitrogen) by Lipofectamine 2000. Transfected cells were then seeded into 100 mm dishes at various cell density and were grown in DMEM growth medium containing G418 at 400 μg/ml and Zeocin at 200 μg/ml. G418- and Zeocin-resistant colony cells were assayed for their ability to complement the growth of CJ2-gD2, benchmarked against U2CEP4R-11 cells. V0R-124 cells represent a G418/Zeocin-resistant stable cell line that can complement the plaque-formation of a control virus CJ2-gD2 efficiently even at passage 41. The plaque-forming efficacy of control CJ2-gD2 in V0R-124 cells is ˜4.5-fold lower than that of U2CEP4R-11 cells and is 3,378-fold higher than that of V0-584 cells. The plaque-forming efficiency of N2-lacZ on V0R-124 cells is similar to that of V0-584 cells (data not shown). Notably, V0R-124 cells are morphologically similar to CCL-81 cells and exhibit similar growth kinetics as CCL-81 cells. These cells are further described further in U.S. Application Ser. No. 62/515,260, Filed on Jun. 5, 2017.

These cells are for instance also used to similarly generate a tetR, ICP0 and VP5-expressing Vero cell line by transfection in V0R-124 cells of a VP5 expression cassette along with DNA encoding hygromycin-B resistant gene. The resulting cells can be used to complement recombinant HSV viruses that do not express ICP0 and UL19 (VP5), such as QF-VAC that is described in the following experiment.

Example 5

QF-VAC, a Further HSV-2 Virus that Over-Expresses gB2, gD2 and does not Express ICP0 and gG2.

Herein, a vaccine candidate is described that possesses the key immunogenicity features of CJ2-gD2/gB2, such as overexpression of gD2 and gB2 at the immediate-early stage of viral infection, and deletions of ICP0 and gG2, while ensuring its inability to produce infectious virus particles through deletion of the HSV-2 essential gene UL19, which encodes the HSV-2 major capsid protein VP5.

Specifically, QF-VAC represents a novel HSV-2 ICP0-, gG2-, and UL19-minus recombinant virus, that encodes:

1) a codon-optimized gD2 gene under the control of the tetO-containing HSV-1 ICP4 promoter at the UL26/UL27 intergenic region, and

2) a codon-diversified gD2 gene under the control of the tetO-containing HSV-1 immediate-early ICP27 promoter at the UL19 locus displacing the UL19 gene.

Because 1) deletion of UL19 has no effect on de novo viral DNA replication, the resulting recombinant virus will express all HSV-2 genes except ICP0, gG2, and VP5, and 2) QF-VAC encodes 2 recombinant copies of the gD2 gene controlled by immediate-early promoters, in addition to one recombinant copy of gB2 under control of the tetO-containing immediate-early HSV-1 ICP0 promoter at the gG2 locus, we expect that overall vaccine efficacy of QF-VAC is at least comparable to and may actually be further enhanced compared to CJ2-gD2/gB2. Unlike CJ2-gD2/gB2, QF-VAC does not express dominant-negative HSV UL9-C535C protein.

Construction of CJ2-gD2/gB2-lacZ, a CJ2-gD2/gB2-Derived Recombinant Virus, in which the lacZ Gene Cassette is Inserted at the Intergenic Region Between the UL26 and UL27 Genes

Description of Plasmids p2UL2627-v and p2UL2627-lacZ

p2UL26.27-v contains a synthesized DNA fragment consisting of 1) HSV-2 DNA sequence consisting of 900 bp upstream of HSV-2 UL26 poly A signal to 110 bp downstream of UL26 poly A signal sequence, 2) DNA sequence containing a modified ICP27 promoter in which the ICP27 TATA element is changed to HCMV TATATAA followed by part of 5′ untranslated region of HSV-1 ICP4 and ICP27, MCS and a synthetic poly A signal sequence, and 3) HSV-2 DNA sequence consisting of 121 bp downstream of the HSV-2 UL27 poly A signal to 873 bp upstream of UL27 poly A signal. p2UL2627-lacZ is a p2UL2627-v-derived plasmid that encodes the lacZ gene under the control of the modified HSV-1 ICP27 promoter.

CJ2-gD2/gB2-lacZ is a CJ2-gD2/gB2-derived recombinant virus, in which the lacZ gene under the control of HSV-1 ICP27 promoter is inserted into the intergenic region of UL26 and UL27 genes. CJ2-gD2/gB2-lacZ was generated by co-transfecting U2OS cells with XhoI/XmnI-linearized p2UL2627-lacZ and pcDNA-3-tetR (Yao, et al., Mol. Ther. 13:1133-41 (2006)) followed by superinfection with CJ2-gD2/gB2 as previously described (Lu, et al., J. Invest. Dermatol. 129:1174-84 (2009)). The lacZ-expressing viruses were then selected and plaque-purified on U2CEP4R-11 cells.

CJ2-gD2/gB2-lacZ was a third-round plaque-purified CJ2-gD2/gB2-derived recombinant virus that exhibits uniform blue plaques in U2CEP4R-11 cells. The plaque-forming efficiency of CJ2-gD2/gB2-lacZ in U2CEP4R-11 cells in the absence of tetracycline is 39,200-fold higher than in the presence of tetracycline, indicating that like CJ2-gD2/gB2, CJ2-gD2/gB-lacZ can express high-level of UL9-C535C in the absence of tetracycline repressor, tetR. Additionally, like CJ2-gD2/gB2, CJ2-gD2/gB2-lacZ replicates efficiently in U2CEP4R-11 cells in the absence of tetracycline. CJ2-gD2/gB2-lacZ was propagated and titered in U2CEP4R-11 cells.

Construction of Q0N-lacZ, a CJ2-gD2/gB2-lacZ-Derived Recombinant Virus, in which the UL9-C535C/gD2 Cassette at the ICP0 Loci Will be Deleted

Description of Plasmid p2ICP0-V

p2ICP0-V is an HSV-2 ICP0 locus-specific shuttle plasmid, which contains 1) a PCR amplified HSV-2 ICP0 DNA fragment covering −762 bp to −21 bp upstream of HSV-2 ICP0 ORF, 2) a multiple cloning site, and 3) a PCR-amplified HSV-2 DNA sequence containing +14 bp to +1406 bp downstream of the HSV-2 ICP0 stop codon. The amplified 5′ and 3′ ICP0 flanking sequences exhibit 99% sequence homology compared to the corresponding ICP0 flanking sequences from HSV-2 strain SD90e (GenBank: KF781518.1). The annotated sequence is provided as SEQ ID NO: 36.

Generation and Testing of Q0N-lacZ Virus Clones

Q0N-lacZ virus will be generated by co-transfection of linearized p2ICP0-V and infectious, early passage CJ2-gD2/gB2-lacZ viral DNA into V0R-124 or U2CEP4R-11 cells as previously described. The progeny virus will be first amplified in V0-584 cells, an HSV-1 ICP0-expressing Vero cell line, followed by first-round plaque purification on V0-584 cells. Individual single large plaques will be picked and amplified in V0-584 cells. Following viral DNA isolation, PCR analysis will be performed with primers specific to the 5′ and 3′ ICP0 flanking sequence. p2ICP0-V plasmid and CJ2-gD2/gB2-lacZ viral DNA will be used as control. Q0N-lacZ will not contain any sequence that overlaps with the HSV-1 ICP0 ORF sequence in V0R-124 cells.

Viruses with the confirmed complete deletion of UL9-C535C/gD2 cassette will be further analyzed by 1) X-Gal staining to confirm their ability to efficiently express the lacZ gene located in the UL26/UL27 intergenic region, 2) PCR analysis to confirm the presence of the codon-optimized gB2 gene at the gG2 locus, 3) their replication-efficiency in V0-584 cells as compared with N2-lacZ, and 4) Western blot analysis to examine their efficiency in expressing gB2 using N2-lacZ and CJ2-gD2/gB2-lacZ and CJ2-gD2/gB2 controls. In addition, Western blots will be also performed with gD2- and ICP27-specific antibodies as previously described. The final Q0N-lacZ virus clone will be subjected to a third round of plaque purification.

Generation of Q0N-gD2, a Q0N-lacZ Derived Virus in which the lacZ Gene in the UL26/UL27 Intergenic Region Will be Replaced with a Codon-Optimized gD2 Under Control of the HSV-1 ICP4-tetO Promoter

Construction of Plasmid p2UL2627TO-gD2

p2UL2627TO-gD2 will be a p2UL2627-v-derived plasmid that encodes the codon-optimized gD2 gene (derived from strain 333) under the control of the wild-type HSV-1 ICP4-tetO promoter with the BGH poly-A signal sequence at the 3′ end of the gD2 gene. The annotated sequence is provided as SEQ ID NO: 24.

Generation and Testing of Q0N-gD2 Virus Clones.

Q0N-gD2 will be generated by co-transfection of U2CEP4R-11 cells or U2OS cells with linearized p2UL2627TO-gD2 and infectious Q0N-lacZ viral DNA. Transfected cells will be harvested at 72 h post-transfection.

X-Gal selection. Progeny viruses will be screened for the recombinational replacement of the lacZ gene of Q0N-lacZ with the gD2-containing DNA sequence of p2UL2627TO-gD2 by standard plaque assays on U2OS cells followed by X-Gal staining of plaques at 72 h post-infection. White plaques, reflecting the replacement of the lacZ gene by the gD2-containing DNA sequence of p2UL2627TO-gD2, will be isolated. The isolated individual (white) plaques will be amplified in V0R-124 cells and subjected to three rounds of plaque purification.

Viruses derived from amplification/plaque purification of individual (white) plaques will be tested for their ability to efficiently express gD2 and gB2 in Vero cells by Western-blot analyses with antibodies specific for gD2, gB2, and ICP27 as previously describe. N2-lacZ, Q0N-lacZ, CJ2-gD2/gB2 and wild-type HSV-2 will be included in these studies as controls.

Verification of genomic location. The genomic location of the codon-optimized gD2 gene at the UL26/UL27 intergenic region in Q0N-gD2 will be verified by PCR analysis with UL26 and UL27 locus-specific primers that flank the gD2 insert and primers specific for codon-optimized gD2.

Replication in V0R-124 cells as compared to CJ2-gD2/gB2. Upon confirming the insertion of codon-optimized gD2 at the UL26/UL27 intergenic region, the replication efficiency of these viruses in V0R-124 cells will be examined by plaque assays. As control, Q0N-lacZ, CJ2-gD2/gB2 will be included in these studies. Q0N-gD2 is expected to exhibit similar replication efficiency as Q0N-lacZ and CJ2-gD2/gB2 in V0R-124 cells.

Construction of QF5-lacZ, a Q0N-gD2-Derived Recombinant Virus, in which the HSV-2 UL19 Gene Will be Replaced with the lacZ Gene Under the Control of the HSV-1 ICP27 Promoter

Construction of p2UL19-V and p2UL19-lacZ

p2UL19-V will be an HSV-2 UL19 (VP5) locus-specific shuttle plasmid, which will contain 1) a PCR-amplified DNA sequence covering 1465 bp upstream of the HSV-2 VP5 TATA element to 1 bp downstream of the VP5 TATA box, 2) the modified HSV-1 ICP27 promoter followed by a multiple cloning region, and 3) a PCR amplified DNA sequences covering 16 bp to 1256 bp downstream of the VP5 stop codon. The viral DNA used for PCR-amplification of described HSV-2 VP5 flanking sequences was isolated from CJ2-gD2/gB2-infected V0R-124 cells. The amplified 5′ and 3′ HSV-2 VP5 flanking sequences will be sequenced and compared with the corresponding HSV-2 strain SD90e VP5 flanking sequence (GenBank: KF781518.1).

p2UL19-lacZ will be a p2UL19-V-derived plasmid that encodes the lacZ gene under the control of the HSV-1 ICP27 promoter.

Construction and Testing of QF5-lacZ Virus Clones

The linearized p2UL19-lacZ vector and infectious Q0N-gD2 viral DNA will be co-transfected into V0R5 cells, a V0R-124-derived HSV-2 VP5-expressing cell line, with Lipofectamine 2000 mediated transfection. The transfected cells will be harvested at 72 h post-transfection.

X-Gal selection. Progeny viruses will be screened for the recombinational replacement of the VP5 ORF-containing fragment at the VP5 locus of Q0N-gD2 with the lacZ gene by standard plaque assays. Plaques will be stained with X-Gal at 72 h post-infection. Blue plaques, reflecting the replacement of the VP5 ORF at the VP5 locus by the lacZ gene of p2UL19-lacZ, will be isolated and amplified in V0R5 cells. The isolated individual (blue) plaques will be amplified in RVP-5 and/or V0R5 cells and subjected to three rounds of plaque purification.

Viruses derived from amplification/plaque purification of individual (blue) plaques will be tested for their ability to efficiently express gD2, gB2, and HSV-2 late gene gC2 in Vero cells by Western-blot analyses with antibodies specific for gD2, gB2, gC2, and ICP27 as previously described. Q0N-gD2, CJ2-gD2/gB2 and wild-type HSV-2 will be included in these studies.

Replication in V0R5 cells as compared to N2-lacZ and CJ2-gD2/gB2. Upon confirming the insertion of lacZ in the UL19 locus, the replication efficiency (PFU/mL) of these viruses in V0R5 cells will be examined by plaque assay. As controls, CJ2-gD2/gB2 and Q0N-lacZ will be included. In addition, the growth kinetics and the replication efficiency of QF5-lacZ will be compared with Q0N-gD2 in V0R5 cells. QF5-lacZ is expected to exhibit similar replication efficiency as Q0N-gD2 in V0R5 cells.

Replication deficiency testing. The replication-incompetency of QF5-lacZ will be determined by standard plaque assay on monolayers of the non-complementing cell lines, Vero and V0R-124. We expect that no replication competent virus/plaques will be detected in Vero cells and V0R-124 cells.

Construction and Characterization of QF-VAC, a QF5-lacZ-Derived Recombinant Virus in which the lacZ Gene at the HSV-2 UL19 Locus Will be Replaced with a HSV-2 gD2 Gene Under the Control of the HSV-1 ICP27-TetO Promoter

Construction of Plasmid p2UL19-gD2

p2UL19-gD2 will be a p2UL19-V derived plasmid that encodes the gD2 gene under the control of the HSV-1 ICP27-tetO promoter. Alternatively, p2UL19-gD2 will be a p2UL19-V derived plasmid that encodes the gD2 gene under the control of the HSV-1 ICP4-tetO promoter.

Construction and Testing of QF-VAC Virus Clones

QF-VAC will be generated by co-transfection of V0R5 cells with linearized p2UL19-gD2 and infectious QF5-lacZ viral DNA. Transfected cells will be harvested at 72 h post-transfection.

X-Gal selection. Progeny viruses will be screened for the recombinational replacement of the lacZ gene at the VP5 locus of QF5-lacZ with the codon-diversified gD2 gene by standard plaque assays. Plaques will be stained with X-Gal at 72 h post-infection. White plaques, reflecting the replacement of the lacZ gene at the VP5 locus by the gD2 gene of p2UL19-gD2, will be isolated and amplified in V0R5 cells and subjected to three rounds of plaque purification.

Viruses derived from amplification/plaque purification of individual (white) plaques will be tested for their ability to efficiently express gD2 and gB2, and HSV-2 late gene gC2 in Vero cells using Western blot analyses with antibodies specific for gD2, gB2, gC2, UL19 and ICP27 as previously described (13). Q0N-gD2, QF5-lacZ, CJ2-gD2/gB2, and wild-type HSV-2 will be included in these studies. QF-VAC is expected to express gD2 and gB2 to at least similar levels as CJ2-gD2/gB2 in infected Vero cells.

Verification of genomic location. The genomic location of the inserted gD2 gene at the UL19 locus in QF-VAC will be verified by PCR analysis with UL19 locus-specific primers that flank the inserted gD2 gene and primers specific for this particular gD2 gene.

Replication in V0R5 cells as compared to Q0N-lacZ and CJ2-gD2/gB2. Upon confirming the insertion of gD2 in the UL19 locus, the replication efficiency (PFU/mL) of these viruses in V0R5 cells will be examined by plaque assays. CJ2-gD2/gB2 and Q0N-lacZ will be included as controls. In addition, the growth kinetics and the replication efficiency of QF-VAC will be compared with QF5-LacZ in V0R5 cells. QF-VAC is expected to exhibit similar replication efficiency as QF5-LacZ in V0R5 cells.

Replication deficiency testing. The replication-defective nature of QF-VAC will be determined by standard plaque assay on monolayers of non-complementing Vero and V0R-124 cells. We expect that no replication competent virus/plaques will be detected in Vero cells and V0R-124 cells.

All references cited herein are fully incorporated by reference. Having now fully described the invention, it will be understood by those of skill in the art that the invention may be practiced within a wide and equivalent range of conditions, parameters and the like, without affecting the spirit or scope of the invention or any embodiment thereof.

Sequences

1. gG2 sequence: −900 to −2 bp upstream of gG2 ORF (SEQ ID NO: 01) CGTCAAGGCGGGGTGGTACGCCAGCACGAGCCACGAGGCGCGGCTGCTGAGACGCCTGAACC ACCCCGCGATCCTACCCCTCCTGGACCTGCACGTCGTTTCTGGGGTCACGTGTCTGGTCCTC CCCAAGTATCACTGCGACCTGTATACCTATCTGAGCAAGCGCCCGTCTCCGTTGGGCCACCT ACAGATAACCGCGGTCTCCCGGCAGCTCTTGAGCGCCATCGACTACGTCCACTGCAAAGGCA TCATCCACCGCGATATTAAGACCGAGAACATCTTCATCAACACCCCCGAGAACATCTGTCTG GGGGACTTTGGGGCGGCGTGCTTTGTGCGCGGGTGTCGATCGAGCCCCTTCCATTACGGGAT CGCAGGCACCATCGATACAAACGCCCCCGAGGTCCTGGCCGGGGATCCGTACACCCAGGTAA TCGACATCTGGAGCGCCGGCCTGGTGATCTTTGAGACCGCCGTCCACACCGCGTCCTTGTTC TCGGCCCCGCGCGACCCCGAAAGGCGGCCGTGCGACAACCAGATCGCGCGCATCATCCGACA GGCCCAGGTACACGTCGACGAGTTTCCGACGCACGCGGAATCGCGCCTCACCGCGCACTACC GCTCGCGGGCGGCCGGGAACAATCGTCCGGCGTGGACCCGACCGGCGTGGACCCGCTACTAC AAGATCCACACAGACGTCGAATATCTCATATGCAAAGCCCTTACCTTTGACGCGGCGCTCCG CCCAAGCGCCGCGGAGTTGCTGCGCCTGCCGCTATTTCACCCTAAGTGACCCCGCTCCCCCC GGGGGGCGTGGAGGGGGGGGCTGGTTGGATGTTTTTGCACAAAAAGACGCGGCCCTCGGGCT TTGGTGTTTTTGGCACCTTGCCGCCCGGCGT 2. poly A signal of HSV-1 ICP27 sequence: (SEQ ID NO: 02) CAAATATTTTTATTGCAACTCCCTGTTTTAGGTACAATAAAAACAAAACATTTCAAA CAAATCGCCCCTCGTGTTGTCCTTCTTTGCTCATGGCCGGCGG 3. TetO-bearing modified HSV-1 ICP0 promoter plus part of 5′ untranslated region of ICP0 gene: (SEQ ID NO: 03) TAATGGGCAACCCCGGTATTCCCCGCCTCCCGCGCCGCGCGTAACCACTCCCCTGGGGTTCC GGGTTATGCTAATTGCTTTTTTGGCGGAACACACGGCCCCTCGCGCATTGGCCCGCGGGTCG CTCAATGAACCCGCATTGGTCCCCTGGGGTTCCGGGTATGGTAATGAGTTTCTTCGGGAAGG CGGGAAGCCCCGGGGCACCGACGCAGGCCAAGCCCCTGTTGCGTCGGCGGGAGGGGCATGCT AATGGGGTTCTTTGGGGGACACCGGGTTGGGCCCCCAAATCGGGGGCCGGGCCGTGCATGCT AATGATATTCTTTGGGGGCGCCGGGTTGGTCCCCGGGGACGGGGCCGCCCCGCGGTGGGCCT GCCTCCCCTGGGACGCGCGGCCATTGGGGGAATCGTCACTGCCGCCCCTTTGGGGAGGGGAA AGGCGTGGGG TATATAAGCAGAGCTCTCCCTATCAGTGATAGAGATCTCCCTATCAGTGATA GAGATCGTCGACGAGCTCGCG TGTCGCATTTGCACCTCGGCACTCGGAGCGAGACGCAGCAG CCAGGCAGACTCGGGCCGCCCCCTCTCCGCATCACCACAGAAGCCCCGCCTACGTTGCGACC CCCAGGG 4. gG2 sequence: +1 to +900 bp downstream of gG2 ORF stop codon (SEQ ID NO: 04) GGGGTGGGGGTGGGGGGCGAGAAACGATGAAGGACGGGAAAGGGAACAGCGACCAAATGTCA CGATAAGAACAATAAACCTGTGACGTCAATCAGATATGTGAGTTTGGTTGTGTTTTGTGGGA CTGGGGGCGGGGGGTGGGAGGTATCAGTGGGTGACAGAGTCTTTTAAAAGACGTGTCCCGGG GCCCTCGAGATGCGCAACTTTTGGCCACACAGAGAAAGGCCCCCAGACGAAGTCACCCGGGT CCCCGAACAAAAACAAAAACCTTGACCGCCGCCGGGGGGCGTGCCTGTTGTTTTGGTCTCAA TGGATCGGTATGCCGTTCGGACCTGGGGGATTGTGGGAATCCTCGGGTGTGCTGCTGTTGGG GCCGCACCCACCGGCCCCGCGTCCGATACAACAAACGCGACCGCACGCCTCCCCACGCACCC CCCACTCATCCGTTCCGGGGGCTTTGCCGTCCCCCTCATCGTGGGGGGGCTGTGTCTCATGA TTCTGGGGATGGCGTGTCTACTCGAGGTCCTGCGTCGCCTGGGTCGCGAGTTGGCGAGGTGC TGCCCCCACGCGGGCCAATTTGCCCCATGATTTTTCGCCTTTCTGGCCTTGCCCCCACCCCA TCGCCCCGATTGTGTGTCGGGTGCCCGGGGTACAGCAGCTATGGAGCGGTCGGTAATATAAC TITGGTTGTCGCCACACGCCCCGTGCCGGGCATGGGTTGTGCGGGAAGGACGAAATAATCCG GCGATCCCCAAGCGTACCAACTGGGGGGGGGGGGGGGGGGGAAAAGAAACTAAAAACACATC AAGCCCACAACCCATCCCACAATGGGGGTTATGGCGGACCCACCGCACCACCATACTCCGAT TCGACCACATATGCAACCAAATCACCCCCAGA 5. Multiple cloning sites of pCDNA3 (SEQ ID NO: 05) AAGCTTGGTCGATATCTATCGGAGCTGTGCTAGCGCCACTGGCGGCCGCTGCAGCGAGCGGA ATTCT 6. HSV-2 gG2 locus-specific vector sequences plus the modified tetO-bearing HSV-1 ICP0 promoter sequences in pgG2-TO. (SEQ ID NO: 06) CAGCTG cgtcaaggcggggtggtacgccagcacgagccacgaggcgcggctgctgagacgcc tgaaccaccccgcgatcctacccctcctggacctgcacgtcgtttctggggtcacgtgtctg gtcctccccaagtatcactgcgacctgtatacctatctgagcaagcgcccgtctccgttggg ccacctacagataaccgcggtctcccggcagctcttgagcgccatcgactacgtccactgca aaggcatcatccaccgcgatattaagaccgagaacatcttcatcaacacccccgagaacatc tgtctgggggactttggggcggcgtgctttgtgcgcgggtgtcgatcgagccccttccatta cgggatcgcaggcaccatcgatacaaacgcccccgaggtcctggccggggatccgtacaccc aggtaatcgacatctggagcgccggcctggtgatctttgagaccgccgtccacaccgcgtcc ttgttctcggccccgcgcgaccccgaaaggcggccgtgcgacaaccagatcgcgcgcatcat ccgacaggcccaggtacacgtcgacgagtttccgacgcacgcggaatcgcgcctcaccgcgc actaccgctcgcgggcggccgggaacaatcgtccggcgtggacccgaccggcgtggacccgc tactacaagatccacacagacgtcgaatatctcatatgcaaagcccttacctttgacgcggc gctccgcccaagcgccgcggagttgctgcgcctgccgctatttcaccctaagtgaccccgct ccccccggggggcgtggaggggggggctggttggatgtttttgcacaaaaagacgcggccct cgggctttggtgtttttggcaccttgccgcccggcgt ACCGGTACTAGTCAATTG CAAATAT TTTTATTGCAACTCCCTGTTTTAGGTACAATAAAAACAAAACATTTCAAACAAATCGCCCCT CGTGTTGTCCTTCTTTGCTCATGGCCGGCGG GGTACCGTTAAGATACGTAACGCG TAATGGG CAACCCCGGTATTCCCCGCCTCCCGCGCCGCGCGTAACCACTCCCCTGGGGTTCCGGGTTAT GCTAATTGCTTTTTTGGCGGAACACACGGCCCCTCGCGCATTGGCCCGCGGGTCGCTCAATG AACCCGCATTGGTCCCCTGGGGTTCCGGGTATGGTAATGAGTTTCTTCGGGAAGGCGGGAAG CCCCGGGGCACCGACGCAGGCCAAGCCCCTGTTGCGTCGGCGGGAGGGGCATGCTAATGGGG TTCTTTGGGGGACACCGGGTTGGGCCCCCAAATCGGGGGCCGGGCCGTGCATGCTAATGATA TTCTTTGGGGGCGCCGGGTTGGTCCCCGGGGACGGGGCCGCCCCGCGGTGGGCCTGCCTCCC CTGGGACGCGCGGCCATTGGGGGAATCGTCACTGCCGCCCCTTTGGGGAGGGGAAAGGCGTG GGG

GCAGAGCTCTCCCTATCAGTGATAGAGATCTCCCTATCAGTGATAGAGATCG TCGACGAGCTCGCGTGTCGCATTTGCACCTCGGCACTCGGAGCGAGACGCAGCAGCCAGGCA GACTCGGGCCGCCCCCTCTCCGCATCACCACAGAAGCCCCGCCTACGTTGCGACCCCCAGGG AAGCTTGGTCGATATCTATCGGAGCTGTGCTAGCGCCACTGGCGGCCGCTGCAGCGAGCGGA ATTCT ggggtgggggtggggggcgagaaacgatgaaggacgggaaagggaacagcgaccaaa tgtcacgataagaacaataaacctgtgacgtcaatcagatatgtgagtttggttgtgttttg tgggactgggggcggggggtgggaggtatcagtgggtgacagagtcttttaaaagacgtgtc ccggggccctcgagatgcgcaacttttggccacacagagaaaggcccccagacgaagtcacc cgggtccccgaacaaaaacaaaaaccttgaccgccgccggggggcgtgcctgttgttttggt ctcaatggatcggtatgccgttcggacctgggggattgtgggaatcctcgggtgtgctgctg ttggggccgcacccaccggccccgcgtccgatacaacaaacgcgaccgcacgcctccccacg caccccccactcatccgttccgggggctttgccgtccccctcatcgtgggggggctgtgtct catgattctggggatggcgtgtctactcgaggtcctgcgtcgcctgggtcgcgagttggcga ggtgctgcccccacgcgggccaatttgccccatgatttttcgcctttctggccttgccccca ccccatcgccccgattgtgtgtcgggtgcccggggtacagcagctatggagcggtcggtaat ataactttggttgtcgccacacgccccgtgccgggcatgggttgtgcgggaaggacgaaata atccggcgatccccaagcgtaccaactgggggggggggggggggggaaaagaaactaaaaac acatcaagcccacaacccatcccacaatgggggttatggcggacccaccgcaccaccatact ccgattcgaccacatatgcaaccaaatcacccccaga TCTAGA

In SEQ ID NO: 06, the elements shown are highlighted as follows along the sequence: a) a first restriction site (bold and underlined); b) the sequence from −900 to −2 bp upstream of the gG2 open reading frame (ordinary lower case text); c) a second restriction site sequence containing one or more restriction enzyme sites (bold and underlined); d) the poly A signal sequence of HSV-1 ICP27 (capitalized text in italics); e) a third restriction site sequence containing one or more restriction enzyme sites (bold and italics); f) the tetO-bearing modified HSV-1 ICP0 promoter plus part of 5′ untranslated region of ICP0 gene (in ordinary capitalized text) with the TATA element shown in bold, underlined and in italics; g) a fourth sequence consisting of multiple restriction sites (bold and underlined); h) the sequence from +1 to +900 bp downstream of the gG2 ORF stop codon (ordinary lower case text); and h) a final restriction site (bold and underlined).

7. Codon-optimized gB2 codon sequence plus Kozak consensus sequence(indicated by low and uppercase letters) (SEQ ID NO: 07) acttAAGCTTgccaccATGAGAGGCGGCGGCCTGATCTGCGCCCTGGTGGTGGGCGCCCTGG TGGCCGCCGTGGCCAGCGCCGCCCCCGCCGCCCCCGCCGCCCCCAGAGCCAGCGGCGGCGTG GCCGCCACCGTGGCCGCCAACGGCGGCCCCGCCAGCAGACCCCCCCCCGTGCCCAGCCCCGC CACCACCAAGGCCAGAAAGAGAAAGACCAAGAAGCCCCCCAAGAGACCCGAGGCCACCCCCC CCCCCGACGCCAACGCCACCGTGGCCGCCGGCCACGCCACCCTGAGAGCCCACCTGAGAGAG ATCAAGGTGGAGAACGCCGACGCCCAGTTCTACGTGTGCCCCCCCCCCACCGGCGCCACCGT GGTGCAGTTCGAGCAGCCCAGAAGATGCCCCACCAGACCCGAGGGCCAGAACTACACCGAGG GCATCGCCGTGGTGTTCAAGGAGAACATCGCCCCCTACAAGTTCAAGGCCACCATGTACTAC AAGGACGTGACCGTGAGCCAGGTGTGGTTCGGCCACAGATACAGCCAGTTCATGGGCATCTT CGAGGACAGAGCCCCCGTGCCCTTCGAGGAGGTGATCGACAAGATCAACGCCAAGGGCGTGT GCAGAAGCACCGCCAAGTACGTGAGAAACAACATGGAGACCACCGCCTTCCACAGAGACGAC CACGAGACCGACATGGAGCTGAAGCCCGCCAAGGTGGCCACCAGAACCAGCAGAGGCTGGCA CACCACCGACCTGAAGTACAACCCCAGCAGAGTGGAGGCCTTCCACAGATACGGCACCACCG TGAACTGCATCGTGGAGGAGGTGGACGCCAGAAGCGTGTACCCCTACGACGAGTTCGTGCTG GCCACCGGCGACTTCGTGTACATGAGCCCCTTCTACGGCTACAGAGAGGGCAGCCACACCGA GCACACCAGCTACGCCGCCGACAGATTCAAGCAGGTGGACGGCTTCTACGCCAGAGACCTGA CCACCAAGGCCAGAGCCACCAGCCCCACCACCAGAAACCTGCTGACCACCCCCAAGTTCACC GTGGCCTGGGACTGGGTGCCCAAGAGACCCGCCGTGTGCACCATGACCAAGTGGCAGGAGGT GGACGAGATGCTGAGAGCCGAGTACGGCGGCAGCTTCAGATTCAGCAGCGACGCCATCAGCA CCACCTTCACCACCAACCTGACCCAGTACAGCCTGAGCAGAGTGGACCTGGGCGACTGCATC GGCAGAGACGCCAGAGAGGCCATCGACAGAATGTTCGCCAGAAAGTACAACGCCACCCACAT CAAGGTGGGCCAGCCCCAGTACTACCTGGCCACCGGCGGCTTCCTGATCGCCTACCAGCCCC TGCTGAGCAACACCCTGGCCGAGCTGTACGTGAGAGAGTACATGAGAGAGCAGGACAGAAAG CCCAGAAACGCCACCCCCGCCCCCCTGAGAGAGGCCCCCAGCGCCAACGCCAGCGTGGAGAG AATCAAGACCACCAGCAGCATCGAGTTCGCCAGACTGCAGTTCACCTACAACCACATCCAGA GACACGTGAACGACATGCTGGGCAGAATCGCCGTGGCCTGGTGCGAGCTGCAGAACCACGAG CTGACCCTGTGGAACGAGGCCAGAAAGCTGAACCCCAACGCCATCGCCAGCGCCACCGTGGG CAGAAGAGTGAGCGCCAGAATGCTGGGCGACGTGATGGCCGTGAGCACCTGCGTGCCCGTGG CCCCCGACAACGTGATCGTGCAGAACAGCATGAGAGTGAGCAGCAGACCCGGCACCTGCTAC AGCAGACCCCTGGTGAGCTTCAGATACGAGGACCAGGGCCCCCTGATCGAGGGCCAGCTGGG CGAGAACAACGAGCTGAGACTGACCAGAGACGCCCTGGAGCCCTGCACCGTGGGCCACAGAA GATACTTCATCTTCGGCGGCGGCTACGTGTACTTCGAGGAGTACGCCTACAGCCACCAGCTG AGCAGAGCCGACGTGACCACCGTGAGCACCTTCATCGACCTGAACATCACCATGCTGGAGGA CCACGAGTTCGTGCCCCTGGAGGTGTACACCAGACACGAGATCAAGGACAGCGGCCTGCTGG ACTACACCGAGGTGCAGAGAAGAAACCAGCTGCACGACCTGAGATTCGCCGACATCGACACC GTGATCAGAGCCGACGCCAACGCCGCCATGTTCGCCGGCCTGTGCGCCTTCTTCGAGGGCAT GGGCGACCTGGGCAGAGCCGTGGGCAAGGTGGTGATGGGCGTGGTGGGCGGCGTGGTGAGCG CCGTGAGCGGCGTGAGCAGCTTCATGAGCAACCCCTTCGGCGCCCTGGCCGTGGGCCTGCTG GTGCTGGCCGGCCTGGTGGCCGCCTTCTTCGCCTTCAGATACGTGCTGCAGCTGCAGAGAAA CCCCATGAAGGCCCTGTACCCCCTGACCACCAAGGAGCTGAAGACCAGCGACCCCGGCGGCG TGGGCGGCGAGGGCGAGGAGGGCGCCGAGGGCGGCGGCTTCGACGAGGCCAAGCTGGCCGAG GCCAGAGAGATGATCAGATACATGGCCCTGGTGAGCGCCATGGAGAGAACCGAGCACAAGGC CAGAAAGAAGGGCACCAGCGCCCTGCTGAGCAGCAAGGTGACCAACATGGTGCTGAGAAAGA GAAACAAGGCCAGATACAGCCCCCTGCACAACGAGGACGAGGCCGGCGACGAGGACGAGCTG TAGaggagctagcGAATTCtgc 8. Modified HSV-1 ICP0 promoter with hCMV TATA element plus part of 5′ untranslated region of ICP0 gene: hCMV TATA element underlined. (SEQ ID NO: 08) TAATGGGCAACCCCGGTATTCCCCGCCTCCCGCGCCGCGCGTAACCACTCCCCTGGGGTTCC GGGTTATGCTAATTGCTTTTTTGGCGGAACACACGGCCCCTCGCGCATTGGCCCGCGGGTCG CTCAATGAACCCGCATTGGTCCCCTGGGGTTCCGGGTATGGTAATGAGTTTCTTCGGGAAGG CGGGAAGCCCCGGGGCACCGACGCAGGCCAAGCCCCTGTTGCGTCGGCGGGAGGGGCATGCT AATGGGGTTCTTTGGGGGACACCGGGTTGGGCCCCCAAATCGGGGGCCGGGCCGTGCATGCT AATGATATTCTTTGGGGGCGCCGGGTTGGTCCCCGGGGACGGGGCCGCCCCGCGGTGGGCCT GCCTCCCCTGGGACGCGCGGCCATTGGGGGAATCGTCACTGCCGCCCCTTTGGGGAGGGGAA AGGCGTGGGG TATATAAGCAGAGCTC GTCGCATTTGCACCTCGGCACTCGGAGCGAGACGCA GCAGCCAGGCAGACTCGGGCCGCCCCCTCTCCGCATCACCACAGAAGCCCCGCCTACGTTGC GACCCCCAGGG 9. TetO-containing DNA sequence (underlined sequence represents  two tandem tet operators)  (SEQ ID NO: 09)  TCCCTATCAGTGATAGAGATCTCCCTATCAGTGATAGAGA TCGTCGACGAGCTCGCGT  10. Two tandem tet operator sequence  (SEQ ID NO: 10) TCCCTATCAGTGATAGAGATCTCCCTATCAGTGATAGAGA SEQ ID NO's 11-13 are in text of specification: SEQ ID NO: 11 is a Tet operator op2 element; SEQ ID NO: 12 and 13 are TATA elements.  11. HSV-1 UL9-0535C coding sequence (SEQ ID NO: 14)  (SEQ ID NO: 14)  ATGGGAGAGG CGTCGCTGCC GGCCCAGGCC GCCGAGACGG AGGAGGTGGG  TCTTTTGTCG AAAAATACCT CCGGTCCGAT GTCGCGCCGG CGGAAATTGT  CGCGCTCATG CGCAACCTCA ACAGCCTGAT GGGACGCACG CGGTTTATTT  ACCTGGCGTT GCTGGAGGCC TGTCTCCGCG TTCCCATGGC CACCCGCAGC  AGCGCCATAT TTCGGCGGAT CTATGACCAC TACGCCACGG GCGTCATCCC  CACGATCAAC GTCACCGGAG AGCTGGAGCT CGTGGCCCTG CCCCCCACCC  TGAACGTAAC CCCCGTCTGG GAGCTGTTGT GCCTGTGCAG CACCATGGCC  GCGCGCCTGC ATTGGGACTC GGCGGCCGGG GGATCTGGGA GGACCTTCGG  CCCCGATGAC GTGCTGGACC TACTGACCCC CCACTACGAC CGCTACATGC  AGCTGGTGTT CGAACTGGGC CACTGTAACG TAACCGACGG ACTTCTGCTC  TCGGAGGAAG CCGTCAAGCG CGTCGCCGAC GCCCTAAGCG GCTGTCCCCC  GCGCGGGTCC GTTAGCGAGA CGGACCACGC GGTGGCGCTG TTCAAGATAA  TCTGGGGCGA ACTGTTTGGC GTGCAGATGG CCAAAAGCAC GCAGACGTTT  CCCGGGGCGG GGCGCGTTAA AAACCTCACC AAACAGACAA TCGTGGGGTT  GTTGGACGCC CACCACATCG ACCACAGCGC CTGCCGGACC CACAGGCAGC  TGTACGCCCT GCTTATGGCC CACAAGCGGG AGTTTGCGGG CGCGCGCTTC  AAGCTACGCG TGCCCGCGTG GGGGCGCTGT TTGCGCACGC ACTCATCCAG  CGCCAACCCC AACGCTGACA TCATCCTGGA GGCGGCGCTG TCGGAGCTCC  CCACCGAGGC CTGGCCCATG ATGCAGGGGG CGGTGAACTT TAGCACCCTA TAA  12. HSV-2 gD2 Genbank Number K01498 (SEQ ID NO: 15) (SEQ ID NO: 15) CTTGGGGGGG GGGGGGAAGA AACTAAAAAC ACATCAAGCC CACAACCCAT  CCCACAAGGG GGGTTATGGC GGACCCACCG CACCACCATA CTCCGATTCG  ACCACATATG CAACCAAATC ACCCCCAGAG GGGAGGTTCC ATTTTTACGA  GGAGGAGGAG TATAATAGAG TCTTTGTGTT TAAAACCCGG GGTCGGTGTG  GTGTTCGGTC ATAAGCTGCA TTGCGAACCA CTAGTCGCCG TTTTTCGTGT  GCATCGCGTA TCACGGCATG GGGCGTTTGA CCTCCGGCGT CGGGACGGCG  GCCCTGCTAG TTGTCGCGGT GGGACTCCGC GTCGTCTGCG CCAAATACGC  CTTAGCAGAC CCCTCGCTTA AGATGGCCGA TCCCAATCGA TTTCGCGGGA  AGAACCTTCC GGTTTTGGAC CAGCTGACCG ACCCCCCCGG GGTGAAGCGT  GTTTACCACA TTCAGCCGAG CCTGGAGGAC CCGTTCCAGC CCCCCAGCAT  CCCGATCACT GTGTACTACG CAGTGCTGGA ACGTGCCTGC CGCAGCGTGC  TCCTACATGC CCCATCGGAG GCCCCCCAGA TCGTGCGCGG GGCTTCGGAC  GAGGCCCGAA AGCACACGTA CAACCTGACC ATCGCCTGGT ATCGCATGGG  AGACAATTGC GCTATCCCCA TCACGGTTAT GGAATACACC GAGTGCCCCT  ACAACAAGTC GTTGGGGGTC TGCCCCATCC GAACGCAGCC CCGCTGGAGC  TACTATGACA GCTTTAGCGC CGTCAGCGAG GATAACCTGG GATTCCTGAT  GCACGCCCCC GCCTTCGAGA CCGCGGGTAC GTACCTGCGG CTAGTGAAGA  TAAACGACTG GACGGAGATC ACACAATTTA TCCTGGAGCA CCGGGCCCGC  GCCTCCTGCA AGTACGCTCT CCCCCTGCGC ATCCCCCCGG CAGCGTGCCT  CACCTCGAAG GCCTACCAAC AGGGCGTGAC GGTCGACAGC ATCGGGATGT  TACCCCGCTT TATCCCCGAA AACCAGCGCA CCGTCGCCCT ATACAGCTTA  AAAATCGCCG GGTGGCACGG CCCCAAGCCC CCGTACACCA GCACCCTGCT  GCCGCCGGAG CTGTCCGACA CCACCAACGC CACGCAACCC GAACTCGTTC  CGGAAGACCC CGAGGACTCG GCCCTCTTAG AGGATCCCGC CGGGACGGTG  TCTTCGCAGA TCCCCCCAAA CTGGCACATC CCGTCGATCC AGGACGTCGC  GCCGCACCAC GCCCCCGCCG CCCCCAGCAA CCCGGGCCTG ATCATCGGCG  CGCTGGCCGG CAGTACCCTG GCGGCGCTGG TCATCGGCGG TATTGCGTTT  TGGGTACGCC GCCGCGCTCA GATGGCCCCC AAGCGCCTAC GTCTCCCCCA  CATCCGGGAT GACGACGCGC CCCCCTCGCA CCAGCCATTG TTTTACTAGA  GGAGTTTCCC CGTTCCCGTG TACCTCTGGG CCCGTGTGGG AGGGTGGCCG  GGGTATTTGG GTGGGACTTG GACTCCGCAT AAAGGGAGTC TCGAAGGAGG  GAAACTAGGA CAGTTCATAG GCCGGGAGCG TGGGGCGCGC ACCGCGTCCC  GACGATTAGC CACCGCGCCC ACAGCCACCT CGACC  13. HSV-1 ICP0 promoter sequence plus 5′ untranslated region of ICP0  (SEQ ID NO: 16) TAATGGGCAACCCCGGTATTCCCCGCCTCCCGCGCCGCGCGTAACCACTCCCCTGGGGTTCC  GGGTTATGCTAATTGCTTTTTTGGCGGAACACACGGCCCCTCGCGCATTGGCCCGCGGGTCG  CTCAATGAACCCGCATTGGTCCCCTGGGGTTCCGGGTATGGTAATGAGTTTCTTCGGGAAGG  CGGGAAGCCCCGGGGCACCGACGCAGGCCAAGCCCCTGTTGCGTCGGCGGGAGGGGCATGCT  AATGGGGTTCTTTGGGGGACACCGGGTTGGGCCCCCAAATCGGGGGCCGGGCCGTGCATGCT  AATGATATTCTTTGGGGGCGCCGGGTTGGTCCCCGGGGACGGGGCCGCCCCGCGGTGGGCCT  GCCTCCCCTGGGACGCGCGGCCATTGGGGGAATCGTCACTGCCGCCCCTTTGGGGAGGGGAA  AGGCGTGGGG TATAAGT TAGCCCTGGCCCGACAGTCTG G TCGCATTTGCACCTCGGCACTCG  GAGCGAGACGCAGCAGCCAGGCAGACTCGGGCCGCCCCCTCTCCGCATCACCACAGAAGCCC  CGCCTACGTTGCGACCCCCAGGGACCCTCCGTCCGCGACCCTCCAGCCGCATACGACCCC 

In SEQ ID NO: 16, the underlined single G represents the transcription start site of ICP0 gene, and the TATA element for ICP0 gene is TATAAGT.

14. HSV2 gD protein sequence (HSV-2, strain SD90e, GenBank: KF781518.1) (SEQ ID NO: 17) MGRLTSGVGTAALLVVAVGLRVVCAKYALADPSLKMADPNRFRGKNLPVLDQLTDPPGVKRV YHIQPSLEDPFQPPSIPITVYYAVLERACRSVLLHAPSEAPQIVRGASDEARKHTYNLTIAW YRMGDNCAIPITVMEYTECPYNKSLGVCPIRTQPRWSYYDSFSAVSEDNLGFLMHAPAFETA GTYLRLVKINDWTEITQFILEHRARASCKYALPLRIPPAACLTSKAYQQGVTVDSIGMLPRF IPENQRTVALYSLKIAGWHGPKPPYTSTLLPPELSDTTNATQPELVPEDPEDSALLEDPAGT VSSQIPPNWHIPSIQDVAPHHAPAAPSNPGLIIGALAGSTLAVLVIGGIAFWVRRRAQMAPK RLRLPHIRDDDAPPSHQPLFY 15. HSV2 gB protein sequence (HSV-2, strain SD90e, GenBank: KF781518.1) (SEQ ID NO: 18) MRGGGLICALVVGALVAAVASAAPAAPRASGGVAATVAANGGPASRPPPVPSPATTRARKRK TKKPPERPEATPPPDANATVAAGHATLRAHLREIKVENADAQFYVCPPPTGATVVQFEQPRR CPTRPEGQNYTEGIAVVFKENIAPYKFKATMYYKDVTVSQVWFGHRYSQFMGIFEDRAPVPF EEVIDKINAKGVCRSTAKYVRNNMETTAFHRDDHETDMELKPAKVATRTSRGWHTTDLKYNP SRVEAFHRYGTTVNCIVEEVDARSVYPYDEFVLATGDFVYMSPFYGYREGSHTEHTSYAADR FKQVDGFYARDLTTKARATSPTTRNLLTTPKFTVAWDWVPKRPAVCTMTKWQEVDEMLRAEY GGSFRFSSDAISTTFTTNLTQYSLSRVDLGDCIGRDAREAIDRMFARKYNATHIKVGQPQYY LATGGFLIAYQPLLSNTLAELYVREYMREQDRKPRNATPAPLREAPSANASVERIKTTSSIE FARLQFTYNHIQRHVNDMLGRIAVAWCELQNHELTLWNEARKLNPNAIASATVGRRVSARML GDVMAVSTCVPVAPDNVIVQNSMRVSSRPGTCYSRPLVSFRYEDQGPLIEGQLGENNELRLT RDALEPCTVGHRRYFIFGGGYVYFEEYAYSHQLSRADVTTVSTFIDLNITMLEDHEFVPLEV YTRHEIKDSGLLDYTEVQRRNQLHDLRFADIDTVIRADANAAMFAGLCAFFEGMGDLGRAVG KVVMGVVGGVVSAVSGVSSFMSNPFGALAVGLLVLAGLVAAFFAFRYVLQLQRNPMKALYPL TTKELKTSDPGGVGGEGEEGAEGGGFDEAKLAEAREMIRYMALVSAMERTEHKARKKGTSAL LSSKVTNMVLRKRNKARYSPLHNEDEAGDEDEL 16. HSV2 gG protein sequence (HSV-2, strain SD90e, GenBank: KF781518.1) (SEQ ID NO: 19) MHAIAPRLLLLFVLSGLPGTRGGSGVPGPINPPNNDVVFPGGSPVAQYCYAYPRLDDPGPLG SADAGRQDLPRRVVRHEPLGRSFLTGGLVLLAPPVRGFGAPNATYAARVTYYRLTRACRQPI LLRQYGGCRGGEPPSPKTCGSYTYTYQGGGPPTRYALVNASLLVPIWDRAAETFEYQIELGG ELHVGLLWVEVGGEGPGPTAPPQAARAEGGPCVPPVPAGRPWRSVPPVWYSAPNPGFRGLRF RERCLPPQTPAAPSDLPRVAFAPQSLLVGITGRTFIRMARPTEDVGVLPPHWAPGALDDGPY APFPPRPRFRRALRTDPEGVDPDVRAPLTGRRLMALTEDASSDSPTSAPEKTPLPVSATAMA PSVDPSAEPTAPATTTPPDEMATQAATVAVTPEETAVASPPATASVESSPLPAAAATPGAGH TNTSSAPAAKTPPTTPAPTTPPPTSTHATPRPTTPGPQTTPPGPATPGPVGASAAPTADSPL TASPPATAPGPSAANVSVAATTATPGTRGTARTPPTDPKTHPHGPADAPPGSPAPPPPEHRG GPEEFEGAGDGEPPDDDDSATGLAFRTPNPNKPPPARPGPIRPTLPPGILGPLAPNTPRPPA QAPAKDMPSGPTPQHIPLFWFLTASPALDILFIISTTIHTAAFVCLVALAAQLWRGRAGRRR YAHPSVRYVCLPPERD 17. HSV-1 UL9 protein sequence (HSV-1, strain KOS, GenBank: JQ673480) (SEQ ID NO: 20) MPFVGGAESGDPLGAGRPIGDDECEQYTSSVSLARMLYGGDLAEWVPRVHPKTTIERQQHGP VTFPNASAPTARCVTVVRAPMGSGKTTALIRWLREAIHSPDTSVLVVSCRRSFTQTLATRFA ESGLVDFVTYFSSTNYIMNDRPFHRLIVQVESLHRVGPNLLNNYDVLVLDEVMSTLGQLYSP TMQQLGRVDALMLRLLRTCPRIIAMDATANAQLVDFLCGLRGEKNVHVVVGEYAMPGFSARR CLFLPRLGTELLQAALRPPGPPSGPSPDASPDARGATFFGELEARLGGGDNICIFSSTVSFA EIVARFCRQFTDRVLLLHSLTPLGDVTTWGQYRVVIYTTVVTVGLSFDPLHFDGMFAYVKPM NYGPDMVSVYQSLGRVRTLRKGELLIYMDGSGARSEPVFTPMLLNHVVSSCGQWPAQFSQVT NLLCRRFKGRCDASACDTSLGRGSRIYNKFRYKHYFERCTLACLSDSLNILHMLLTLNCIRV RFWGHDDTLTPKDFCLFLRGVHFDALRAQRDLRELRCRDPEASLPAQAAETEEVGLFVEKYL RSDVAPAEIVALMRNLNSLMGRTRFIYLALLEACLRVPMATRSSAIFRRIYDHYATGVIPTI NVTGELELVALPPTLNVTPVWELLCLCSTMAARLHWDSAAGGSGRTFGPDDVLDLLTPHYDR YMQLVFELGHCNVTDGLLLSEEAVKRVADALSGCPPRGSVSETDHAVALFKIIWGELFGVQM AKSTQTFPGAGRVKNLTKQTIVGLLDAHHIDHSACRTHRQLYALLMAHKREFAGARFKLRVP AWGRCLRTHSSSANPNADIILEAALSELPTEAWPMMQGAVNFSTL 18. UL9-0535C protein sequence (MG plus UL9 amino acid 537 to 851) (SEQ ID NO: 21) MGEASLPAQAAETEEVGLFVEKYLRSDVAPAEIVALMRNLNSLMGRTRFIYLALLEACLRVP MATRSSAIFRRIYDHYATGVIPTINVTGELELVALPPTLNVTPVWELLCLCSTMAARLHWDS AAGGSGRTFGPDDVLDLLTPHYDRYMQLVFELGHCNVTDGLLLSEEAVKRVADALSGCPPRG SVSETDHAVALFKIIWGELFGVQMAKSTQTFPGAGRVKNLTKQTIVGLLDAHHIDHSACRTH RQLYALLMAHKREFAGARFKLRVPAWGRCLRTHSSSANPNADIILEAALSELPTEAWPMMQG AVNFSTL 19. HSV-1 ICP27 promoter (strain KOS): (SEQ ID NO: 22) CAACGACCCCGCCCATGGGTCCCAATTGGCCGTCCCGTTACCAAGACCAACCCAGCCAGCGT ATCCACCCCCGCCCGGGTCCCCGCGGAAGCGGAACGGGGTATGTGATATGCTAATTAAATAC ATGCCACGTACTTATGGTGTCTGATTGGTCCTTGTCTGTGCCGGAGGTGGGGCGGGGGCCCC GCCCGGGGGGCGGAACGAGGAGGGGTTTGGGAGAGCCGGCCCCGGCACCACGGGTATAAGGA CATCCACCACC 20. HSV-2 ICP27 promoter (Strain IIG52): (SEQ ID NO: 23) GCCGATCCGG CCTCGGGTCT GCTTGCCCCT CCCCCGGCCC AGCACAGGCA GGCTCGTCCG ACTTCCGCAT ACACCCCACC CTACCGCGTG CTTCCGCACC CCCGCCTACG CGTGTACGCG AAGGCGGACC CAGACCTGCC GTATGCTAAT TAAATACATA AAACCCACCC TCGGTGTCCG ATTGGTTTCT GGGGACGGCG GGGGCGGGGG CGGTGACGCC CGACGGGGAG GGACAAGGAG GAGTTTCGGA AAGCCGGCCC CGGTCGTGCG GGTATAAGGG CAGCCACCGG CCCACTGGGC GC 21. ICP4/TO promoter, codon-optimized gD2, and BGH poly A: (SEQ ID NO: 24) caattgaagcttcgtacgGGGCCCCGCCCCCTGCCCGTTCCTCGTTAGCATGCGGAACGGAA GCGGAAACCGCCGGATCGGGCGGTAATGAGATGCCATGCGGGGCGGGGCGCGGACCCACCCG CCCTCGCGCCCCGCCCATGGCAGATGGCGCGGATGGGCGGGGCCGGGGGTTCGACCAACGGG CCGCGGCCACGGGCCCCCGGCGTGCCGGCGTCGGGGCGGGGTCGTGCATAATGGAATTCCGT TCGGGGTGGGCCCGCCGGGGGGGCGGGGGGCCGGCGGCCTCCGCTGCTCCTCCTTCCCGCCG GCCCCTGGGACTATATGAGCCGAGCTCTCCCTATCAGTGATAGAGATCTCCCTATCAGTGAT AGAGATCGTCGACGAGCTCGCGTGTGCATCGCGTATCACGGCgccacc

 

AGGAGTTTCC CCGCTCCCGTGTACCTCTGGGCCCGTGTGGGAGGGTGGCTGGGGTATTTGGGTGGGACTTGG ACTCCGCATAAAGGGAGTCTCGAAGGAGGGAACC GCTGATCAGCCTCGACTGTGCCTTCTAG TTGCCAGCCATCTGTTGTTTGCCCCTCCCCCGTGCCTTCCTTGACCCTGGAAGGTGCCACTC CCACTGTCCTTTCCT

ATGAGGAAATTGCATCGCATTGTCTGAGTAGGTGTCATTCT ATTCTGGGGGGTGGGGTGGGGCAGGACAGCAAGGGGGAGGATTGGGAAGACAATAGCAGGCA TGC gatatctacgcaacgaccccgcccatgggtcccaattggatcctctaga

In SEQ ID NO: 24, bold italic represents the codon-optimized gD2 coding sequence; italic represents a part of the 3′ untranslated region of gD2; underlined italic represents BGH poly A signal sequence.

22. p2UL26.27-v: (SEQ ID NO: 25) tgccggccgcggggacggtggcctacggacaccccggcgccggcccgtccccgcactacccg cctcctcccgcccacccgtacccgggtatgctgttcgcgggccccagtcccctggaggccca gatcgccgcgctggtgggggccatcgccgccgaccgccaggcgggtgggcttccggcggccg ccggagaccacgggatccgggggtcggcgaagcgccgccgacacgaggtggagcagccggag tacgactgcggccgtgacgagccggaccgggacttcccgtattacccgggcgaggcccgccc cgagccgcgcccggtcgactcccggcgcgccgcgcgccaggcttccgggccccacgaaacca tcacggcgctggtgggggcggtgacgtccctgcagcaggaactggcgcacatgcgcgcgcgt acccacgccccctacgggccgtatccgccggtggggccctaccaccacccccacgcagacac ggagacccccgcccaaccaccccgctaccccgccaaggccgtctatctgccgccgccgcaca tcgcccccccggggcctcctctatccggggcggtccccccaccctcgtatcccccagttgcg gttacccccggtcccgctcccccgctacatcagccctcccccgcacacgcccacccccctcc gccgccgccgggacccacgcctccccccgccgcgagcttaccccaacccgaggcgcccggcg cggaggccggcgccttagttaacgccagcagcgcggcccacgtgaacgtggacacggcccgg gccgccgatctgtttgtgtcacagatgatggggtcccgctaactcgcctccaggatccggac ttggggggggtgtgtgttttcatatattttaaataaacaaacaaccggacaaaagtataccc acttcgtgtgcttgtgtttttgtttgagaggggggggtggagtgggggggaaagtgggccga atgacacaaaaattaggtcgtacgCAACGACCCCGCCCATGGGTCCCAATTGGCCGTCCCGT TACCAAGACCAACCCAGCCAGCGTATCCACCCCCGCCCGGGTCCCCGCGGAAGCGGAACGGG GTATGTGATATGCTAATTAAATACATGCCACGTACTTATGGTGTCTGATTGGTCCTTGTCTG TGCCGGAGGTGGGGCGGGGGCCCCGCCCGGGGGGCGGAACGAGGAGGGGTTTGGGAGAGCCG GCCCCGGCACCACGGGTATATAAGCAACCGGTgtcgacggcgggggtcgtcggggtccgtgg gtctcgccccctccccccatcgagagtccgtaggtgacctaccgtTGCGCCACCACCAGAGG CCATATCCGACACCCCAGCCCCGACGGCAGCCGACAGCCCGAAGCTTGGTCGATATCTATCG GAGCTGTGCTAGCGCCACTGGTACCCGAGCGGAATTCTGTCTAGAAATGGTTACAAATAAAA GATCTTTATTTTCATTAGATCTGTGTGTTGGTTTTTTGTGTGttggttttcccgttagcaca tgtctgcatttgtttttctagtcacacgccccccccccccaaataaaaaccaaggcaaaaca ataccagaagtcatgtgtatttttgaacatcggtgtctttttatttatacacaagcccagct cccctcccctcccttagagctcgtcttcgtctccggcctcgtcctcgttgtggagcggagag tacctggctttgttgcgcttgcgcagaaccatgttggtgaccttggagctgagcagggcgct cgtgcccttctttctggccttgtgttccgtgcgctccatggccgacaccaaagccatatatc ggatcatttctcgggcctcggccaacttggcctcgtcaaacccgcccccctccgcgccttcc tccccctccccgcccacgcccccggggtcggaagtcttgagttccttggtggtgagcggata cagggccttcatgggattgcgttgcagttgcaggacgtagcggaaggcgaagaaggccgcga ccaggccggccaggaccagcagccccacggcaagcgccccgaaggggttggacataaaggag gacacgcccgagacggccgacaccacgccccccactactcccatgactaccttgccgaccgc gcgccccaagtcccccatcccctcgaagaacgcgcacagccccgcgaacatggcggcgttgg cgtcggcgcggatgaccgtgtcgatgtcggcaaagcgcaggtcgtgcagctggttgcggcgc tggacctccgtgtagtccagcaggccgctgtccttgatctcgtggcgcgtgtagacctccag gggcacaaactcgtggtcctccagcatggtgatgttcaggtcgatgaaggtgctgacggtgg tgacgtcggcgcgactcagctggtgagagtacgcgtactcctcgaagtacacgtagcccccg ccgaagatgaagtagcgccggtggcccacggtgcacggctcgagcgcgtc 23. 900 bp upstream of HSV-2 UL26 poly A signal to 110 bp downstream of UL26 poly A signal: (SEQ ID NO: 26) tgccggccgcggggacggtggcctacggacaccccggcgccggcccgtccccgcactacccg cctcctcccgcccacccgtacccgggtatgctgttcgcgggccccagtcccctggaggccca gatcgccgcgctggtgggggccatcgccgccgaccgccaggcgggtgggcttccggcggccg ccggagaccacgggatccgggggtcggcgaagcgccgccgacacgaggtggagcagccggag tacgactgcggccgtgacgagccggaccgggacttcccgtattacccgggcgaggcccgccc cgagccgcgcccggtcgactcccggcgcgccgcgcgccaggcttccgggccccacgaaac catcacggcgctggtgggggcggtgacgtccctgcagcaggaactggcgcacatgcgcgc gcgtacccacgccccctacgggccgtatccgccggtggggccctaccaccacccccacgc agacacggagacccccgcccaaccaccccgctaccccgccaaggccgtctatctgccgcc gccgcacatcgcccccccggggcctcctctatccggggcggtccccccaccctcgtatcc cccagttgcggttacccccggtcccgctcccccgctacatcagccctcccccgcacacgc ccacccccctccgccgccgccgggacccacgcctccccccgccgcgagcttaccccaacc cgaggcgcccggcgcggaggccggcgccttagttaacgccagcagcgcggcccacgtgaa cgtggacacggcccgggccgccgatctgtttgtgtcacagatgatggggtcccgctaact cgcctccaggatccggacttggggggggtgtgtgttttcatatattttaaataaacaaac aaccggacaaaagtatacccacttcgtgtgcttgtgtttttgtttgagaggggggggtgg agtgggggggaaagtgggccgaatgacacaaaaattaggt 24. 121 bp downstream of HSV-2 UL27 poly A signal to 873 bp upstream of UL27 poly A signal: (SEQ ID NO: 27) ttggttttcc cgttagcaca tgtctgcatt tgtttttcta gtcacacgcc cccccccccc aaataaaaac caaggcaaaa caataccaga agtcatgtgt atttttgaac atcggtgtct ttttatttat acacaagccc agctcccctc ccctccctta gagctcgtct tcgtctccgg cctcgtcctc gttgtggagc ggagagtacc tggctttgtt gcgcttgcgc agaaccatgt tggtgacctt ggagctgagc agggcgctcg tgcccttctt tctggccttg tgttccgtgc gctccatggc cgacaccaaa gccatatatc ggatcatttc tcgggcctcg gccaacttgg cctcgtcaaa cccgcccccc tccgcgcctt cctccccctc cccgcccacg cccccggggt cggaagtctt gagttccttg gtggtgagcg gatacagggc cttcatggga ttgcgttgca gttgcaggac gtagcggaag gcgaagaagg ccgcgaccag gccggccagg accagcagcc ccacggcaag cgccccgaag gggttggaca taaaggagga cacgcccgag acggccgaca ccacgccccc cactactccc atgactacct tgccgaccgc gcgccccaag tcccccatcc cctcgaagaa cgcgcacagc cccgcgaaca tggcggcgtt ggcgtcggcg cggatgaccg tgtcgatgtc ggcaaagcgc aggtcgtgca gctggttgcg gcgctggacc tccgtgtagt ccagcaggcc gctgtccttg atctcgtggc gcgtgtagac ctccaggggc acaaactcgt ggtcctccag catggtgatg ttcaggtcga tgaaggtgct gacggtggtg acgtcggcgc gactcagctg gtgagagtac gcgtactcct cgaagtacac gtagcccccg ccgaagatga agtagcgccg gtggcccacg gtgcacggct cgagcgcgtc 25. A modified HSV-1 ICP27 promoter in which the ICP27 TATA element is changed to HCMV TATATAAG followed by an Age I site and part of 5′ unstranslated region of HSV-1 ICP4 and ICP27, MCS and a synthetic poly A signal sequence: (SEQ ID NO: 28) CAACGACCCCGCCCATGGGTCCCAATTGGCCGTCCCGTTACCAAGACCAACCCAGCCAGCGT ATCCACCCCCGCCCGGGTCCCCGCGGAAGCGGAACGGGGTATGTGATATGCTAATTAAATAC ATGCCACGTACTTATGGTGTCTGATTGGTCCTTGTCTGTGCCGGAGGTGGGGCGGGGGCCCC GCCCGGGGGGCGGAACGAGGAGGGGITTGGGAGAGCCGGCCCCGGCACCACGGGTATATAAG CAACCGGTgtcgacggcgggggtcgtcggggtccgtgggtctcgccccctccccccatcgag agtccgtaggtgacctaccgtTGCGCCACCACCAGAGGCCATATCCGACACCCCAGCCCCGA CGGCAGCCGACAGCCCGAAGCTTGGTCGATATCTATCGGAGCTGTGCTAGCGCCACTGGTAC CCGAGCGGAATTCTGTCTAGAAATGGTTACAAATAAAAGATCTTTATTTTCATTAGATCTGT GTGTTGGTTTTTTGTG TG 26. A newly designed HSV-1 TetO-bearing ICP27 promoter in which the ICP27 TATA element is changed to HCMV TATATAA and TetO sequence is flanked with Age I site followed by part of 5′ unstranslated region of HSV-1 ICP4 and ICP27, MCS and a synthetic poly A signal sequence: (SEQ ID NO: 29) cgtacgCAACGACCCCGCCCATGGGTCCCAATTGGCCGTCCCGTTACCAAGACCAACCCAGC CAGCGTATCCACCCCCGCCCGGGTCCCCGCGGAAGCGGAACGGGGTATGTGATATGCTAATT AAATACATGCCACGTACTTATGGTGTCTGATTGGTCCTTGTCTGTGCCGGAGGTGGGGCGGG GGCCCCGCCCGGGGGGCGGAACGAGGAGGGGTTTGGGAGAGCCGGCCCCGGCACCACGGGTA TATAAGCAACCGGTCTCCCTATCAGTGATAGAGATCTCCCTATCAGTGATAGAGATCGaccg gtgtcgacggcgggggtcgtcggggtccgtgggtctcgccccctccccccatcgagagtccg taggtgacctaccgtTGCGCCACCACCAGAGGCCATATCCGACACCCCAGCCCCGACGGCAG CCGACAGCCCGAAGCTTGGTCGATATCTATCGGAGCTGTGCTAGCGCCACTGGTACCCGAGC GGAATTCTGTCTAGAAATGGTTACA 27. HSV-1 ICP27 promoter: (SEQ ID NO: 30) CAACGACCCCGCCCATGGGTCCCAATTGGCCGTCCCGTTACCAAGACCAACCCAGCCAGCGT ATCCACCCCCGCCCGGGTCCCCGCGGAAGCGGAACGGGGTATGTGATATGCTAATTAAATAC ATGCCACGTACTTATGGTGTCTGATTGGTCCTTGTCTGTGCCGGAGGTGGGGCGGGGGCCCC GCCCGGGGGGCGGAACGAGGAGGGGTTTGGGAGAGCCGGCCCCGGCACCACGGGTATAAGGA CATCCACCACC 28. 5′ untranslated region of HSV-1 ICP27, -49 bp upstream of ICP27 ATG: (SEQ ID NO: 31) TGCGCCACCACCAGAGGCCATATCCGACACCCCAGCCCCGACGGCAGCCGACAGCCCG 29. 5′ untranslated region of HSV-1 ICP4, -126 to -64 bp upstream of ICP4 ATG: (SEQ ID NO: 32) Gtcgacggcgggggtcgtcggggtccgtgggtctcgccccctccccccatcgagagtccgta ggtgacctaccgt 30. Multiple cloning sites: (SEQ ID NO: 33) AAGCTTGGTCGATATCTATCGGAGCTGTGCTAGCGCCACTGGTACCCGAGCGGAATTCTG TCTAGA 31. Synthetic poly A: (SEQ ID NO: 34) AATAAAAGATCTTTATTTTCATTAGATCTGTGTGTTGGTTTTTTGTGTG 32. p2UL2627-lacZ: (SEQ ID NO: 35) tcgcgcgtttcggtgatgacggtgaaaacctctgacacatgcagctcccggagacggtcaca gcttgtctgtaagcggatgccgggagcagacaagcccgtcagggcgcgtcagcgggtgttgg cgggtgtcggggctggcttaactatgcggcatcagagcagattgtactgagagtgcaccata tgtgccggccgcggggacggtggcctacggacaccccggcgccggcccgtccccgcactacc cgcctcctcccgcccacccgtacccgggtatgctgttcgcgggccccagtcccctggaggcc cagatcgccgcgctggtgggggccatcgccgccgaccgccaggcgggtgggcttccggcggc cgccggagaccacgggatccgggggtcggcgaagcgccgccgacacgaggtggagcagccgg agtacgactgcggccgtgacgagccggaccgggacttcccgtattacccgggcgaggcccgc cccgagccgcgcccggtcgactcccggcgcgccgcgcgccaggcttccgggccccacgaaac catcacggcgctggtgggggcggtgacgtccctgcagcaggaactggcgcacatgcgcgcgc gtacccacgccccctacgggccgtatccgccggtggggccctaccaccacccccacgcagac acggagacccccgcccaaccaccccgctaccccgccaaggccgtctatctgccgccgccgca catcgcccccccggggcctcctctatccggggcggtccccccaccctcgtatcccccagttg cggttacccccggtcccgctcccccgctacatcagccctcccccgcacacgcccacccccct ccgccgccgccgggacccacgcctccccccgccgcgagcttaccccaacccgaggcgcccgg cgcggaggccggcgccttagttaacgccagcagcgcggcccacgtgaacgtggacacggccc gggccgccgatctgtttgtgtcacagatgatggggtcccgctaactcgcctccaggatccgg acttggggggggtgtgtgttttcatatattttaaataaacaaacaaccggacaaaagtatac ccacttcgtgtgcttgtgtttttgtttgagaggggggggtggagtgggggggaaagtgggcc gaatgacacaaaaattaggtcgtacgcaacgaccccgcccatgggtcccaattggccgtccc gttaccaagaccaacccagccagcgtatccacccccgcccgggtccccgcggaagcggaacg gggtatgtgatatgctaattaaatacatgccacgtacttatggtgtctgattggtccttgtc tgtgccggaggtggggcgggggccccgcccggggggcggaacgaggaggggtttgggagagc cggccccggcaccacgggtatataagcaaccggtgtcgacggcgggggtcgtcggggtccgt gggtctcgccccctccccccatcgagagtccgtaggtgacctaccgttgcgccaccaccaga ggccatatccgacaccccagccccgacggcagccgacagcccgAGCTTACCATGGGGGGTTC TCATCATCATCATCATCATGGTATGGCTAGCATGACTGGTGGACAGCAAATGGGTCGGGATC TGTACGACGATGACGATAAGGTACCTAAGGATCAGCTTGGAGTTGATCCCGTCGTTTTACAA CGTCGTGACTGGGAAAACCCTGGCGTTACCCAACTTAATCGCCTTGCAGCACATCCCCCTTT CGCCAGCTGGCGTAATAGCGAAGAGGCCCGCACCGATCGCCCTTCCCAACAGTTGCGCAGCC TGAATGGCGAATGGCGCTTTGCCTGGTTTCCGGCACCAGAAGCGGTGCCGGAAAGCTGGCTG GAGTGCGATCTTCCTGAGGCCGATACTGTCGTCGTCCCCTCAAACTGGCAGATGCACGGTTA CGATGCGCCCATCTACACCAACGTAACCTATCCCATTACGGTCAATCCGCCGTTTGTTCCCA CGGAGAATCCGACGGGTTGTTACTCGCTCACATTTAATGTTGATGAAAGCTGGCTACAGGAA GGCCAGACGCGAATTATTTTTGATGGCGTTAACTCGGCGTTTCATCTGTGGTGCAACGGGCG CTGGGTCGGTTACGGCCAGGACAGTCGTTTGCCGTCTGAATTTGACCTGAGCGCATTTTTAC GCGCCGGAGAAAACCGCCTCGCGGTGATGGTGCTGCGTTGGAGTGACGGCAGTTATCTGGAA GATCAGGATATGTGGCGGATGAGCGGCATTTTCCGTGACGTCTCGTTGCTGCATAAACCGAC TACACAAATCAGCGATTTCCATGTTGCCACTCGCTTTAATGATGATTTCAGCCGCGCTGTAC TGGAGGCTGAAGTTCAGATGTGCGGCGAGTTGCGTGACTACCTACGGGTAACAGTTTCTTTA TGGCAGGGTGAAACGCAGGTCGCCAGCGGCACCGCGCCTTTCGGCGGTGAAATTATCGATGA GCGTGGTGGTTATGCCGATCGCGTCACACTACGTCTGAACGTCGAAAACCCGAAACTGTGGA GCGCCGAAATCCCGAATCTCTATCGTGCGGTGGTTGAACTGCACACCGCCGACGGCACGCTG ATTGAAGCAGAAGCCTGCGATGTCGGTTTCCGCGAGGTGCGGATTGAAAATGGTCTGCTGCT GCTGAACGGCAAGCCGTTGCTGATTCGAGGCGTTAACCGTCACGAGCATCATCCTCTGCATG GTCAGGTCATGGATGAGCAGACGATGGTGCAGGATATCCTGCTGATGAAGCAGAACAACTTT AACGCCGTGCGCTGTTCGCATTATCCGAACCATCCGCTGTGGTACACGCTGTGCGACCGCTA CGGCCTGTATGTGGTGGATGAAGCCAATATTGAAACCCACGGCATGGTGCCAATGAATCGTC TGACCGATGATCCGCGCTGGCTACCGGCGATGAGCGAACGCGTAACGCGAATGGTGCAGCGC GATCGTAATCACCCGAGTGTGATCATCTGGTCGCTGGGGAATGAATCAGGCCACGGCGCTAA TCACGACGCGCTGTATCGCTGGATCAAATCTGTCGATCCTTCCCGCCCGGTGCAGTATGAAG GCGGCGGAGCCGACACCACGGCCACCGATATTATTTGCCCGATGTACGCGCGCGTGGATGAA GACCAGCCCTTCCCGGCTGTGCCGAAATGGTCCATCAAAAAATGGCTTTCGCTACCTGGAGA GACGCGCCCGCTGATCCTTTGCGAATACGCCCACGCGATGGGTAACAGTCTTGGCGGTTTCG CTAAATACTGGCAGGCGTTTCGTCAGTATCCCCGTTTACAGGGCGGCTTCGTCTGGGACTGG GTGGATCAGTCGCTGATTAAATATGATGAAAACGGCAACCCGTGGTCGGCTTACGGCGGTGA TTTTGGCGATACGCCGAACGATCGCCAGTTCTGTATGAACGGTCTGGTCTTTGCCGACCGCA CGCCGCATCCAGCGCTGACGGAAGCAAAACACCAGCAGCAGTTTTTCCAGTTCCGTTTATCC GGGCAAACCATCGAAGTGACCAGCGAATACCTGTTCCGTCATAGCGATAACGAGCTCCTGCA CTGGATGGTGGCGCTGGATGGTAAGCCGCTGGCAAGCGGTGAAGTGCCTCTGGATGTCGCTC CACAAGGTAAACAGTTGATTGAACTGCCTGAACTACCGCAGCCGGAGAGCGCCGGGCAACTC TGGCTCACAGTACGCGTAGTGCAACCGAACGCGACCGCATGGTCAGAAGCCGGGCACATCAG CGCCTGGCAGCAGTGGCGTCTGGCGGAAAACCTCAGTGTGACGCTCCCCGCCGCGTCCCACG CCATCCCGCATCTGACCACCAGCGAAATGGATTTTTGCATCGAGCTGGGTAATAAGCGTTGG CAATTTAACCGCCAGTCAGGCTTTCTTTCACAGATGTGGATTGGCGATAAAAAACAACTGCT GACGCCGCTGCGCGATCAGTTCACCCGTGCACCGCTGGATAACGACATTGGCGTAAGTGAAG CGACCCGCATTGACCCTAACGCCTGGGTCGAACGCTGGAAGGCGGCGGGCCATTACCAGGCC GAAGCAGCGTTGTTGCAGTGCACGGCAGATACACTTGCTGATGCGGTGCTGATTACGACCGC TCACGCGTGGCAGCATCAGGGGAAAACCTTATTTATCAGCCGGAAAACCTACCGGATTGATG GTAGTGGTCAAATGGCGATTACCGTTGATGTTGAAGTGGCGAGCGATACACCGCATCCGGCG CGGATTGGCCTGAACTGCCAGCTGGCGCAGGTAGCAGAGCGGGTAAACTGGCTCGGATTAGG GCCGCAAGAAAACTATCCCGACCGCCTTACTGCCGCCTGTTTTGACCGCTGGGATCTGCCAT TGTCAGACATGTATACCCCGTACGTCTTCCCGAGCGAAAACGGTCTGCGCTGCGGGACGCGC GAATTGAATTATGGCCCACACCAGTGGCGCGGCGACTTCCAGTTCAACATCAGCCGCTACAG TCAACAGCAACTGATGGAAACCAGCCATCGCCATCTGCTGCACGCGGAAGAAGGCACATGGC TGAATATCGACGGTTTCCATATGGGGATTGGTGGCGACGACTCCTGGAGCCCGTCAGTATCG GCGGAGTTCCAGCTGAGCGCCGGTCGCTACCATTACCAGTTGGTCTGGTGTCAAAAATAATA AAGCCGAATTCtgtctagaaatggttacaaataaaagatctttattttcattagatctgtgt gttggttttttgtgtgttggttttcccgttagcacatgtctgcatttgtttttctagtcaca cgccccccccccccaaataaaaaccaaggcaaaacaataccagaagtcatgtgtatttttga acatcggtgtctttttatttatacacaagcccagctcccctcccctcccttagagctcgtct tcgtctccggcctcgtcctcgttgtggagcggagagtacctggctttgttgcgcttgcgcag aaccatgttggtgaccttggagctgagcagggcgctcgtgcccttctttctggccttgtgtt ccgtgcgctccatggccgacaccaaagccatatatcggatcatttctcgggcctcggccaac ttggcctcgtcaaacccgcccccctccgcgccttcctccccctccccgcccacgcccccggg gtcggaagtcttgagttccttggtggtgagcggatacagggccttcatgggattgcgttgca gttgcaggacgtagcggaaggcgaagaaggccgcgaccaggccggccaggaccagcagcccc acggcaagcgccccgaaggggttggacataaaggaggacacgcccgagacggccgacaccac gccccccactactcccatgactaccttgccgaccgcgcgccccaagtcccccatcccctcga agaacgcgcacagccccgcgaacatggcggcgttggcgtcggcgcggatgaccgtgtcgatg tcggcaaagcgcaggtcgtgcagctggttgcggcgctggacctccgtgtagtccagcaggcc gctgtccttgatctcgtggcgcgtgtagacctccaggggcacaaactcgtggtcctccagca tggtgatgttcaggtcgatgaaggtgctgacggtggtgacgtcggcgcgactcagctggtga gagtacgcgtactcctcgaagtacacgtagcccccgccgaagatgaagtagcgccggtggcc cacggtgcacggctcgagcttcctcgctcactgactcgctgcgctcggtcgttcggctgcgg cgagcggtatcagctcactcaaaggcggtaatacggttatccacagaatcaggggataacgc aggaaagaacatgtgagcaaaaggccagcaaaaggccaggaaccgtaaaaaggccgcgttgc tggcgtttttccataggctccgcccccctgacgagcatcacaaaaatcgacgctcaagtcag aggtggcgaaacccgacaggactataaagataccaggcgtttccccctggaagctccctcgt gcgctctcctgttccgaccctgccgcttaccggatacctgtccgcctttctcccttcgggaa gcgtggcgctttctcatagctcacgctgtaggtatctcagttcggtgtaggtcgttcgctcc aagctgggctgtgtgcacgaaccccccgttcagcccgaccgctgcgccttatccggtaacta tcgtcttgagtccaacccggtaagacacgacttatcgccactggcagcagccactggtaaca ggattagcagagcgaggtatgtaggcggtgctacagagttcttgaagtggtggcctaactac ggctacactagaaggacagtatttggtatctgcgctctgctgaagccagttaccttcggaaa aagagttggtagctcttgatccggcaaacaaaccaccgctggtagcggtggtttttttgttt gcaagcagcagattacgcgcagaaaaaaaggatctcaagaagatcctttgatcttttctacg gggtctgacgctcagtggaacgaaaactcacgttaagggattttggtcatgagattatcaaa aaggatcttcacctagatccttttaaattaaaaatgaagttttaaatcaatctaaagtatat atgagtaaacttggtctgacagttaccaatgcttaatcagtgaggcacctatctcagcgatc tgtctatttcgttcatccatagttgcctgactccccgtcgtgtagataactacgatacggga gggcttaccatctggccccagtgctgcaatgataccgcgagacccacgctcaccggctccag atttatcagcaataaaccagccagccggaagggccgagcgcagaagtggtcctgcaacttta tccgcctccatccagtctattaattgttgccgggaagctagagtaagtagttcgccagttaa tagtttgcgcaacgttgttgccattgctacaggcatcgtggtgtcacgctcgtcgtttggta tggcttcattcagctccggttcccaacgatcaaggcgagttacatgatcccccatgttgtgc aaaaaagcggttagctccttcggtcctccgatcgttgtcagaagtaagttggccgcagtgtt atcactcatggttatggcagcactgcataattctcttactgtcatgccatccgtaagatgct tttctgtgactggtgagtactcaaccaagtcattctgagaatagtgtatgcggcgaccgagt tgctcttgcccggcgtcaatacgggataataccgcgccacatagcagaactttaaaagtgct catcattggaaaacgttcttcggggcgaaaactctcaaggatcttaccgctgttgagatcca gttcgatgtaacccactcgtgcacccaactgatcttcagcatcttttactttcaccagcgtt tctgggtgagcaaaaacaggaaggcaaaatgccgcaaaaaagggaataagggcgacacggaa atgttgaatactcatactcttcctttttcaatattattgaagcatttatcagggttattgtc tcatgagcggatacatatttgaatgtatttagaaaaataaacaaataggggttccgcgcaca tttccccgaaaagtgccacctgacgtctaagaaaccattattatcatgacattaacctataa aaataggcgtatcacgaggccctttcgtc

In SEQ ID NO: 35, the Italic sequence represents the Hind III/Eco RI-lacZ-containing DNA sequence inserted into p2UL2627-V.

33. Annotated sequence of p2ICPO-V plasmid:  (SEQ ID NO: 36)

TATAAGG

AATAAA

In SEQ ID NO: 36, nucleotide (nt) 189-nt 929 represent 5′ ICP0 flanking sequence; nt 988-nt 2388 represent 3′ ICP0 flanking sequence; and nt 930-nt 987 represents multiple cloning region. The ICP0 TATA Element comprises the following sequence: TATAAGG (SEQ ID NO: 37). The ICP0 POLY A comprises the following sequence: AATAAA (SEQ ID NO: 38), which is 233 nt down stream of ICP0 stop codon TAA (SEQ ID NO: 39).

34. Annotated sequence of p2UL19-V plasmid (SEQ ID NO: 40) tcgcgcgtttcggtgatgacggtgaaaacctctgacacatgcagctcccggagacggtcaca gcttgtctgtaagcggatgccgggagcagacaagcccgtcagggcgcgtcagcgggtgttgg cgggtgtcggggctggcttaactatgcggcatcagagcagattgtactgagagtgcaccata tgtgagaatcccgaggccgccctacggaataaacggaccccccgcacacaaagtaggcgcgg tttctgtctgccgtgacgtaaaacacaacgtcccggtggtgcagggtggtggcatagctgag ctccatggccggcgagccacggggcggacttggggggggggaatagtggggtggtgggagga gggtggtgggagcaagggctggcggtggcgcgaacgggacccgtgggttgctctcgcgcgtg ccgcccgcgcgtagggttgtggccggacggaggaactccccccactgtggatcgcggcgtcg gtgcttgggcaaacgacggcttccgtcacgcacggccggccttttaaggacaactccgggcg cattcccgacgtggccctctgggtgttttcttcgtttcctcccccaacccatctttccccct gccttcccactgactaaccgccacgtcatcagcccgcgggggagggcggacgcacggatgtg cggctcgcgaaccacatccacccatgatttgggcgtcagggcgtgggtgtgaatttcggggg ttccgggcccaacggccgaggtttatatcctgctgggacgtgacttcgccaggcactcgcat ccgcggatactacccgggtgggggttgtgtgtagaacccgcgcggtgcttgtttgattttgg cctccgccccccatccctgaagcttgggtccggacccgggcccgcgccgccagcactacttt cggtttcgctgcctcgccggctccccgcaccgaccatgacaatgcgggatgatgttcctttg ttggatcgcgagctggtagacgaggccgcgtgtggcggggaggacggcgaactgccgctcga tgaacagttttcgctgtcctcgtacggcacgtctgatttttttgtcagttcggcctactcgc gtcttccgccccacacccagccggtcttttccaagcgggtggtgatgtttgcttggtcgttc ctggtcctcaagccgctggagctggtggccgcgggcatgtattacgggtggaccggacgggc ggtggcgccggcatgtattatagccgccgtcctcgcctactatgtcacgtggctggcacggg cgctcctcctgtacgtgaacatcaaacgggatcgcctgccgttgtcgccacccgtgttttgg gggttgtgcgtgatcatgggcggcgcggccctgtgcgccctggtggcggccgcccatgagac gttcagtcccgacgggcttttccattggatcaccgccagccagctgctgccccgcacggatc ccctccgcgcccgttctctgggaatcgcctgcgcggccggcgccgccatgtgggtggcggcg gcggactgctttgccgcctttaccaacttttttctagcacgcttttggaccagggccatctt gaaggcacccgtcgcgttctaacgggggtgtggcgggggggtatataaggcaattggccgtc ccgttaccaagaccaacccagccagcgtatccacccccgcccgggtccccgcggaagcggaa cggggtatgtgatatgctaattaaatacatgccacgtacttatggtgtctgattggtccttg tctgtgccggaggtggggcgggggccccgcccggggggcggaacgaggaggggtttgggaga gccggccccggcaccacgggtatataagcaaccggtgtcgacggcgggggtcgtcggggtcc gtgggtctcgccccctccccccatcgagagtccgtaggtgacctaccgttgcgccaccacca gaggccatatccgacaccccagccccgacggcagccgacagcccgaagcttggtcgatatct atcggagctgtgctagcgccactggtacccgagcggaattctgtctagacccagctttccct ccacccgcccgtcttttttttttcctgtttggggcattgggtttgattttccgacgttgctt ttacccacacacaccccctgtccccgcccccccgggggggcttggactgggagccgcgattc cgagggcaggtcccaataaaacccagacccgagctccgggggactgattctcacctggggct cctgcgcacgacagacctccccgtgcgtgctgctgagccctgccccgccccctctcccacac ggtcggtgccccccatctctgtttcatcatcgtcccggttgcgttgcgctttccggccctcc cgcacccccgcgttccggtgtctcgcggcccggcgccatgatcacggattgtttcgaagcag acatcgcgatcccctcgggtatctcgcgccccgatgccgcggcgctgcagcggtgcgagggt cgagtggtctttctgccgaccatccgccgccagctggcgctcgcggacgtggcgcacgaatc gttcgtctccggaggagttagtcccgacacgttggggttgttgctggcgtaccgcaggcgct tccccgcggtaatcacgcgggtgctgcccacgcgaatcgtcgcctgccccgtggacctgggg ctcacgcacgccggcaccgtcaatctccgcaacacctcccccgtcgacctctgcaacgggga tcccgtcagcctcgtcccgcccgtcttcgagggccaggcgacggacgtgcgcctggagtcgc tggacctcacgctgcggtttccggtcccgctcccaacgcccctggcccgcgagatagtcgcg cggctggtcgcccggggcatccgggacctcaaccccgacccccggacgcccggggagctccc cgacctcaacgtgctgtattacaacggggcccgtctctcgctcgtggccgacgtccagcaac tcgcctccgtaaacaccgagctgcggtcgctcgtcctcaacatggtctactccataaccgaa ggaaccaccctcatcctcacgctcatcccccggctgctcgcgctaagcgcccaggacggata cgtgaacgcgctcctgcagatgcagagcgtcacgcgagaagccgcccagctcatccaccccg aagcccccatgctgatgcaggacggcgagcgcaggctgccgctttacgaggcgctggtcgcc tggctggcgcacgcgggccaactcggggacatcctggccctggccccggctcgagcttcctc gctcactgactcgctgcgctcggtcgttcggctgcggcgagcggtatcagctcactcaaagg cggtaatacggttatccacagaatcaggggataacgcaggaaagaacatgtgagcaaaaggc cagcaaaaggccaggaaccgtaaaaaggccgcgttgctggcgtttttccataggctccgccc ccctgacgagcatcacaaaaatcgacgctcaagtcagaggtggcgaaacccgacaggactat aaagataccaggcgtttccccctggaagctccctcgtgcgctctcctgttccgaccctgccg cttaccggatacctgtccgcctttctcccttcgggaagcgtggcgctttctcatagctcacg ctgtaggtatctcagttcggtgtaggtcgttcgctccaagctgggctgtgtgcacgaacccc ccgttcagcccgaccgctgcgccttatccggtaactatcgtcttgagtccaacccggtaaga cacgacttatcgccactggcagcagccactggtaacaggattagcagagcgaggtatgtagg cggtgctacagagttcttgaagtggtggcctaactacggctacactagaaggacagtatttg gtatctgcgctctgctgaagccagttaccttcggaaaaagagttggtagctcttgatccggc aaacaaaccaccgctggtagcggtggtttttttgtttgcaagcagcagattacgcgcagaaa aaaaggatctcaagaagatcctttgatcttttctacggggtctgacgctcagtggaacgaaa actcacgttaagggattttggtcatgagattatcaaaaaggatcttcacctagatcctttta aattaaaaatgaagttttaaatcaatctaaagtatatatgagtaaacttggtctgacagtta ccaatgcttaatcagtgaggcacctatctcagcgatctgtctatttcgttcatccatagttg cctgactccccgtcgtgtagataactacgatacgggagggcttaccatctggccccagtgct gcaatgataccgcgagacccacgctcaccggctccagatttatcagcaataaaccagccagc cggaagggccgagcgcagaagtggtcctgcaactttatccgcctccatccagtctattaatt gttgccgggaagctagagtaagtagttcgccagttaatagtttgcgcaacgttgttgccatt gctacaggcatcgtggtgtcacgctcgtcgtttggtatggcttcattcagctccggttccca acgatcaaggcgagttacatgatcccccatgttgtgcaaaaaagcggttagctccttcggtc ctccgatcgttgtcagaagtaagttggccgcagtgttatcactcatggttatggcagcactg cataattctcttactgtcatgccatccgtaagatgcttttctgtgactggtgagtactcaac caagtcattctgagaatagtgtatgcggcgaccgagttgctcttgcccggcgtcaatacggg ataataccgcgccacatagcagaactttaaaagtgctcatcattggaaaacgttcttcgggg cgaaaactctcaaggatcttaccgctgttgagatccagttcgatgtaacccactcgtgcacc caactgatcttcagcatcttttactttcaccagcgtttctgggtgagcaaaaacaggaaggc aaaatgccgcaaaaaagggaataagggcgacacggaaatgttgaatactcatactcttcctt tttcaatattattgaagcatttatcagggttattgtctcatgagcggatacatatttgaatg tatttagaaaaataaacaaataggggttccgcgcacatttccccgaaaagtgccacctgacg tctaagaaaccattattatcatgacattaacctataaaaataggcgtatcacgaggcccttt cgtc

In SEQ ID NO: 40, nt 189-nt 1661 represents 5′ UL19 flanking sequence; nt 1663-nt 2029 represents a modified HSV-1 ICP27 promoter containing sequence; and nt 2095-nt 3336 represents a 3′ UL19 flanking sequence. 

What is claimed is:
 1. A replication-defective Herpes simplex virus 2 (HSV-2) recombinant virus, comprising within its genome: a) a first coding sequence, wherein said first coding sequence encodes HSV-2 glycoprotein B (gB2), wherein said first coding sequence is operably linked to a first immediate-early promoter; b) a second coding sequence, wherein said second coding sequence encodes HSV-2 glycoprotein D (gD2), and is operably linked to a second immediate-early promoter; c) a third coding sequence, wherein said third coding sequence encodes HSV-2 glycoprotein D (gD2); and is operably linked to a third immediate-early promoter; and wherein said genome does not comprise a sequence encoding a functional ICP0 protein, and does not comprise a sequence encoding functional HSV-2 gG2 protein.
 2. (canceled)
 3. The recombinant virus of claim 1, wherein said second promoter and third promoter are a HSV-1 or HSV-2 immediate early promoter operably linked to a tetracycline operator (tet-O) sequence; or wherein each of said first, second and third promoters are HSV-1 or HSV-2 immediate early promoters; or wherein each of said first, second and third promoters are selected from the group consisting of an ICP0 promoter, an ICP27 promoter, and an ICP4 promoter; or wherein the first promoter is a HSV-1 or HSV-2 ICP0 promoter; or wherein the first promoter is a modified HSV-1 or HSV-2 ICP0 promoter comprising a human cytomegalovirus (hCMV) TATA element; or wherein the first promoter comprises SEQ ID NO: 08; or wherein said the fourth and fifth promoters are hCMV immediate-early promoters.
 4. The recombinant virus of claim 1, wherein the first coding sequence is located at the gG2 locus of the HSV-2 genome.
 5. The recombinant virus of of claim 1, wherein said genome further does not comprise a sequence encoding a functional UL19 (VP5) protein.
 6. The recombinant virus of claim 1, further comprising a fourth coding sequence, wherein said fourth coding sequence encodes a dominant negative mutant HSV-1 or HSV-2 UL9 protein, and is operably linked to a fourth promoter, wherein said fourth promoter is operably linked to a fourth tet-O sequence.
 7. The recombinant virus of claim 6, further comprising a fifth coding sequence, wherein said fifth coding sequence encodes a dominant negative mutant HSV-1 or HSV-2 UL9 protein, and is operably linked to a fifth promoter, wherein said fifth promoter is operably linked to a fifth tet-O sequence.
 8. The recombinant virus of claim 6, wherein said fourth sequence encodes UL9-C535C.
 9. The recombinant virus of claim 7, wherein said fifth sequence encodes UL9-C535C. 10.-15. (canceled)
 16. The recombinant virus of of claim 1, wherein said first sequence is a codon optimized sequence. 17.-29. (canceled)
 30. A replication defective HSV recombinant virus, comprising a modified HSV-1 or HSV-2 ICP0 promoter comprising a human cytomegalovirus (hCMV) TATA element, wherein said modified promoter is operably linked to a transgene.
 31. The replication defective virus of claim 30, wherein the transgene encodes HSV-2 glycoprotein B (gB).
 32. The replication defective virus of claim 30, wherein said modified promoter comprises SEQ ID NO:
 08. 33. A vaccine comprising the recombinant virus of claim 1 in unit dose form.
 34. A method of immunizing a subject against HSV-1 or HSV-2 infection, comprising administering to said subject the vaccine of claim
 33. 35. The method of claim 34, wherein said subject is seropositive for HSV-1.
 36. The method of claim 34, wherein said subject is seropositive for HSV-2.
 37. The method of claim 34, wherein said subject is seronegative for HSV-1 and HSV-2. 38.-42. (canceled)
 43. A composition comprising the virus of claim
 1. 